Just curious what books I should get and any advice or recommendations as me and two groups of friends are trying to get into dnd. I plan on being a player in one and a DM in the other.

For my player character I am doing a Half-Orc artificer but I was curious if there was a way to make him into a full orc? I plan on playing him as a battle smith, essentially an armored up tank with a lot of attuned items to boost his stats and help with melee but also good at smithing weapons and armor.

For my DM campaign I am sort of at a loss. Back when I was a teenager with no money to buy dnd books I made my own simple rpg system and still have lots of ideas and stories from that but since it's my first campaign should I choose a pre-built option? If I do build the world are there any major things I should consider? I have seen https://vlc****/ a lot of things about whether or not to let gunpowder in and how carry weight is figured out.

I am open to grabbing a few books to just not sure what is best to grab for being a dm vs being a player. Also if I grab some dm books to be a dm in one group can I share the books in another group as a player to my dm for them to use?

Any good channel or website recommendations are welcome and as well as any advice for newer players.

My first recommendation is this:

Don't spend money just yet. There are free basic rules (found in my signature at the bottom of my post, just follow the link; if you can't see it, it's likely that you're on mobile, rotate your screen to landscape and it should appear) and free adventures (some of which can also be found in my signature). That's all you need to get a taste and to decide if you do like it. Do a few adventures and if you have a hunger for more, then crack on and open your wallet.

The following advice is assuming you're ready to spend money:

As a DM (and as a player), you'll definitely want the Player's Handbook. It has most of the rules you'll want, all the classes and many subclasses plus the most common races.

As a player, you can stop there for now. Later purchases to consider are Tasha's Cauldron of Everything (plenty of player options), Xanathar's Guide to Everything (moe oriented to DMs, but still plenty of player options) and Monsters of the Multiverse (33 playable races). There's no point, as a player, getting many other books.

If you're on DDB (not using physical books), you could probably get away with just the PHB even as a DM. Many of the monsters from the Monster Manual are free anyway. However, if you're using physical books, you'll need the Monster Manual, it might also be a boon even if you're on DDB.

Dungeon Master's Guide is optional, in my opinion. It has some useful advanced stuff for DMs, but the essential stuff is in the PHB. Xanathar's Guide to Everything likewise.

For the full Orc player race, it counts as a completely separate race; you'll want to look at Mordenkainen's Monsters of the Multiverse. You can buy individual options (like the Orc) for $1.99 if you wish, it might be cheaper than buying the whole book. If you decide you want the whole book at a later date, that's fine - it'll be discounted by the amount you've paid for the options thus far, so you're not losing anything.

For Battle Smith, you'll be looking at Tasha's Cauldron of Everything. It's available as an individual option as well. You do need to buy at least one Artificer subclass before you can use the Artificer class at all.

As for pre-written versus homebrew...it depends. If you have the time and creative mind, homebrew can be significantly better and cheaper. On the other hand, pre-written is much easier and quicker. You'll still want to tweak it to suit your tastes and style...but the bulk of the work is done for you. If you go pre-written, Forgotten Realms is the most common is similar to Lord of the Rings in tone and style. There are other places that do other themes (Eg, gothic horror, steampunk, etc). That doesn't mean that you can't adapt stories set in one place to work in another, it just takes effort and time. I'm sorry, we can't answer this for you. All I can say, is first work through the free adventures I've provided and see what you like and don't like. You'll soon see if you prefer doing your own thing or just using provided adventures.

In terms of sharing, physical books is obviously up to you to manage. In terms of DDB, you cannot share books for free. What you can do is get a Master Tier Subscription which allows anyone in the same campaign to share their books with everyone else in that campaign. So long as one person, can be anyone, has that sub, then everyone in the same campaign can share any and all of the books anyone else in that campaign owns. It costs $5 a month, I believe.

Critical Role does a series where they play through campaigns (you can find it on YouTube). You don't want to copy them, you need your own style, and they use their own houserules, but they can give inspiration on how to handle things, give you ideas on how to roleplay etc. Again, they're not a perfect ideal model or anything, but just seeing them do stuff might give you that "ooh, I like how he did that, I might nab that for my own game..." experience.

If you have any more questions or need clarification on what I've said, please feel free to ask.

I second Linklite. Do NOT spend money on this hobby until you have at least one or two campaigns under your belt. Additionally, D&D can be played for free without spending a penny. For official content, BR/SRD have everything you need, with EEPC providing a few more species options. If you wantmore content for free, if you are okay with semi-official content, Unearthed Arcana practically has all the playtest versions (and more) of the official published mechanics. In my opinion, mechanics in Unearthed Arcana is generally more fun and powerful compared to the published mechanics. If we include third party homebrew, you can find endless amounts of it online, and Beyond even has a few Critical Role homebrew (blood hunter, gunslinger fighter, cobalt soul monk, open sea paladin).

For play and spending little to no money, you can use graph paper and coins/LEGO minifigures/boardgame pieces if you like having a physical and visual display for combat. You also do not need to spend money on dice either, since you can use Google for that (you type in the dice roll in the search bar, e.g.: 1d8, 2d4, 4d6, 100d20).

TTRPG is a really niche hobby, even among nerds, geeks, and gamers. Half of my friends do not want to try D&D at all, and half of the friends that did try D&D did not want to continue after a few sessions, so I currently have three players (plus me as the GM) who are really up for D&D. So make sure you and your friends actually like the game before you guys spend money.

Once you have a campaign or two under your belt, if you are really sure you want to buy a book, then you will want to get the PHB first. The second book can be XGTE or TCOE; I personally lean towards TCOE, and you should probably get TCOE as well if you really like artificers. The third book will be XGTE or TCOE, whichever one you did not pick for your second. If you want to try more exotic character species there is MP:MOTM (there is also VGTM and MTOF if you want the legacy versions of those species). After that, there is not anything else I would consider essential, and they are generally more niche. There is SCAG if you want some racial feats for a few particular species. VRGTR got dark gifts (dark gifts currently are not supported on Beyond). WGTE and E:RFTLW got Eberron backgrounds and patrons, and warforged as a species. GGTR, MOOT, and S:ACOC got Magic: the Gathering backgrounds and patrons, and MOOT also got piety (like dark gifts, also not supported on Beyond).

As others have said, you don’t need anything but the free basic rules. If you are looking to expand your library I would next get the DMG and the Monster Manual. The rules that are in the PHB are also in the Basic Rules, so you’ll have those already, but the PHB has more subclasses and stuff in it too, so you might want that as well. After that you might want to pick up Xanathar’s Guide as it has some expanded rules in it that are helpful.

While I agree with the "you don't need to buy anything" to play D&D, if you yourself are just learning and planning on starting with a bunch of inexperienced players, there are some modestly priced products designed to teach the game to a new game group through a training/tutorial framework more efficiently than reading through SRD's (which are written more abstractly as a technical reference more than a how to) and chasing down YouTube vids of actual plays etc.  The current starter set Dragons of Stormwreck Isle does a good job at this.  Playing through that will give you hours of play time and you and your players could decide whether the game is worth further investment.  

Going the free resource method without any orientation to the game through other experienced players can be fairly daunting.  There's spending money (Dragons of Stormwreck Isle is $20 and has everything you need to start a game); and there's spending time learning how to play on your own.  Yes you can do the latter without spending any of the former, but modern starter kits are largely written to be played out of the box, with built in coaching you won't find as efficiently packaged elsewhere.