Hi. I am a long time player that has seen many campaigns fizzle out or end for one reason or another. I have never seen one to completion. It so happens that I am the most senior dnd player left in our group and thus I was selected to be the next DM. Yay me xD I am excited, but very nervous. I have slowly been developing a homebrew world to place my players into and would like some feedback from people who know what they are doing. Please and thank you <3 What I have so far is this:

Elves were among the first creations of the Goddess Seldathia. They considered her their Mother and were one with her other creations. The lands they called home and the creatures that shared them. The world was full of magic and life. This was often opposed by the God Mondoth. He embodied darkness and endings. The Elves shunned him and his destructive nature. It was his fault that their Mother lost her connection to the world and was now beyond their reach. And the other races helped him.

Being the oldest race, they have watched the emergence of new races and civilization. The most intrusive of these new races were the humans. While the dwarves and dragonborn had the sense to keep to themselves or the gnomes and fairies had the wisdom to embrace their Mother, the humans were invasive and intrusive. Even the barbaric orcs or untrustworthy tieflings were not as blasphemous to declare their Mother invalid. The humans believed in 12 gods. As their civilization all other the world, they spread their twisted ways. They tracked the days with standardized names and numbers rather than let it be guided by the ever changing seasons or flow of magic. They established trading goods for metals stolen from the heart of Seldathia's Earth. Worse or all, they spread their heresy to the other peoples of their world. The Dwarves worshipped Abuuran, god of the forge, industry and invention. The Ocrs clung to Dothmirus, god pf destruction, death, and endings. Those that once followed their Mother now pledge themselves to Iseda, goddess of nature, or Vidala, goddess of fertility and love. 

The human king had grown too bold. He started encroaching on our sacred lands where we keep the spirit of our Mother alive. Our protests were ignored and our mother insulted. We refused to bend before his arrogance. We waged war against the humans. It was time that they learned their place. Our gift of magic was not granted to he humans and we easily overpowered them. That was, until they committed a great crime. The dwarves discovered crystals  that contained magic deep within the Earth. The humans worked with the dwarves to mine what they called "Arcanite" to create abominations to fight for them in the war against us. Metal men with hearts of magic. They developed machinery to wield magic for them. This gift was denied to their races because the do not respect our Mother, yet they stole it's power.  With these horrors, the humans were capable of withstanding our advances. They even won several devastating victories. All the while, our people could hear our Mother's cries as they ripped out her heart for their own gain. Under this pressure, the war was stopped and a treaty signed.

But that did not stop the humans. Gone mad with their new found power, they continued the mining or Arcanite and advanced their production of magical items. Our people begged for them to stop. Even a few wise souls among their own race pleaded for  the mining to end. The druids that lived in the woods came out of seclusion to petition the nobility. To no avail. Our words fell of deaf ears. 

We now feel something sinister in the flow of magic. The balance has been lost. The animals have gone feral and the trees are restless. They stir deep in the forests. The waves are devastating. Nature itself has risen up against the arrogance of the humans for the defilement of it's most sacred treasure. The call battle has begun.

"Rise my children! We cannot allow for them to steal my very essence! I call upon the Spirits of the Nature, upon the animals of my forests, mountains, plains, and depths, upon the plants the flourish in my Brother's light, and upon those who have my blessing! Defend me from their greed! On this day, they will know my wrath!"

This is a stylized telling from the point of view from the Elves. The players have the option of any starting point (I would love for there to be some from all sides). What they don't know is that the never ending struggle between Seldathia and Mondoth progressed to a massive standoff. During with, and cataclysmic magic explosion  radiated throughout the heavens. The god and goddess split into 12 separate beings. The deities worshipped by the humans. And their influence is far lessoned compared to what it used to be when they were whole. The war and conflict with the Elves and Humans is partially unfounded. The humans did not kill Seldathia, they new her after she was split. The 12 beings the humans and other races worship are essences of the 2 deities, opposing side. Always struggling in their never ending battle, working to maintain the balance.

Any feedback is appreciated. Also, suggestions for a world name would be great. I am awful at naming things.

If you do have folks on multiple sides of the conflict, be careful - that kind of tension within a party can spill into the players themselves, especially if they feel another player is ruining the story they want to tell.  That does not mean you cannot have multiple sides to the conflict within your party, but it does mean you should be prepared to guide players in a way that does not lead to irreconcilable conflict and be prepared to mitigate any such conflict if it comes up.  

For naming, the easiest thing to do is assign each culture a real world language, translate a word associated with the city/town/geographic feature/etc. into that language, then mess with the spelling some so your players can more easily read it. This makes naming things very easy and, more importantly, means you are consistent - humans might, for example, all have towns named using Icelandic words, which will mean they all feel like they etymologically came from the same culture.  

I have a plan to get them together and working towards the same goal in the first encounter. My goal is to have a campaign without a clearly evil side. They are both understandable and have good reasons. The party will act as the middle ground and find lost knowledge to smooth the conflict and restore balance. Their first clue to this will be heavily tight to 2 party members' backstories. They both are tied to a monk monastery that preaches balance (one being a monk with a homebrewed balance subclass and a cleric taken in by the monks). They will have hints along the way that this conflict is not as the opposing nations say it will be.

Also thank you for the name help x.x I have no idea where to start.

Ok, so here’s the thing Sparkle Mage- you are assuming that your players will care about any of that, and there is a good chance that they won’t.  

For instance, when reading your world description, I got about halfway through your opening paragraph before I grew a bit confused, my eyes glazed over, then I got bored and stopped reading.  There is a good chance your players will react the same way.  

Focus on the bread and butter, ESPECIALLY as a new DM. COMBAT.  Get good at running combat quickly and efficiently, while learning the monsters and how to fight them in a tactically challenging way.  DUNGEONS.  Get familiar with creating and presenting dungeons, a discrete environment where the players explore and overcome various obstacles and challenges. ROLEPLAY.  Create NPCs with specific goals and motivations, and have them act independently of the PCs.  This is what creates a living world. 

Lore is great, but only to the extent the players actually care.  Start with a very generic fantasy world, and if they seem intrigued by lore related stuff, then slowly build on that and give them more.  Eventually you can build to a world background like you described, but only if the players were hungry for it to begin with. 

Quote from Sparkle_Mage >>

I have a plan to get them together and working towards the same goal in the first encounter. My goal is to have a campaign without a clearly evil side. They are both understandable and have good reasons. The party will act as the middle ground and find lost knowledge to smooth the conflict and restore balance. Their first clue to this will be heavily tight to 2 party members' backstories. They both are tied to a monk monastery that preaches balance (one being a monk with a homebrewed balance subclass and a cleric taken in by the monks). They will have hints along the way that this conflict is not as the opposing nations say it will be.

Also thank you for the name help x.x I have no idea where to start.

 Players are in my experience just unpredictable. It's the only thing I've ever properly predicted. 

You will as the creator of this lore care a heck of a lot more about the lore than the players unless you give them a reason to. To give you an example I have run three campaigns using the same set up for each group. Some one or something is keeping technological progress limited. Towns never grow to cities before they are brutally destroyed. In this setting the party get taken from the present to some point in the future via a portal/vortex. For one player all they cared about was their family as a human their family were now long gone and lost to them. At every opportunity he was showing others the picture in his locket desperate to find the family. The elves in that same party couldn't have cared less. What's 100 years in a 1000+ year lifespan? In a different group, the players were more curious about how they were brought the the future. Could this power be harnessed for their own purposes? In the third campaign, the group are curious how and why, but it's kind of fallen to a back seat because they're just interested in more event of the week format sessions. So, they don't get world level lore, just town or village level lore. Mainly because they don't care about world level stuff unless it directly affects their character in a way they connect with. 

All of that said...when you know the lore, it makes it all very easier when considering a BBEG, or a conflict. I find knowing the lore helps to frame a future improv moment. I know for example that the world I have created has artefacts that are avatars of the forces/deities of the world. One of those artefacts has been stolen and begun to be corrupted by someone or something that knows the true power of these artefacts. The artefact grows stronger with each act of destruction. The BBEG is drawing the power for eternal life by constantly destroying parts of the world to power the artefact then drawing said energy from the artefact into themselves. None of my players across my three campaigns know this yet. Nor have they picked up on the clues laid down already (I don't think). But knowing this lore helps me to create the sessions and provide a deeper and colourful world for my players. 

So, your lore so far is pretty interesting, but it'll always be more interesting and useful to you, than any of your players at early stages in my opinion.

I disagree with SireSamuel. I think your lore sounds fascinating and as long as you implement it properly and make it interesting and compelling during play (introduce it gradually don’t just dump it all at once) your players are gonna love it too. Also what about Tarwyn for a world name? It just came to me lol.

Also, if not too late, check out the Eberron 5e book. That gives a lot of insight into how to have multiple broad sides in a conflict, of whom none are necessarily bad or worse than one another - just a lot of morally gray.  

Awesome tip, thank you!

What of the dragons? They typically are a driving force in the fantasy worlds. I honestly love your lore for this world, but do you know the geography of your world as of so far? Geography helps you make decisions about the world, such as the backgrounds, races, monsters, and histories. Mythic histories would also help, as they describe the start of the world and the myths of the peoples, helping you discover the nature of your world, hence affecting geography, the foundation of any fantasy world. Cosmology also helps in describing the nature of the world, depending on the major forces found in said cosmology. 
I suggest adding one or two completely original race of major influence in the world, a couple of places of pure magic, and/or an anomaly of great import. Unique features in your world will make it much more unique, helping it to be placed above other, not as memorable worlds. 
Describe the cultures of the peoples; what do they wear, their beliefs, their technology, government, political relations, etc. This will help in making your world unique and alive. Standard rules and well-thought out mechanics also help the world seem more alive. 

I hope that you find my advice helpful, and remember that uniqueness and solidity makes a world seem more alive.