So, I've played most of the classes in the game and just decided to play a warlock. I went with an archfey warlock because it fit with my character concept. I want to build a heavily support based character, and honestly have no idea how to do that with a warlock due to their limited spell slots. I've considered multiclassing into druid or cleric, but I'm not sure which is better. Any help with this would be appreciated.

My stats right now are STR: 8 DEX: 12 CON: 16 INT: 10 WIS: 14  CHA: 16, we used standard array. I made a half-high-elf and took the extra cantrip, but I'm not sure if that's the best idea. I'm probably going to take agonizing blast and book of ancient secrets as my invocations at 2nd level and take pact of the tome as my pact boon. My stats aren't set in stone since we haven't had the first session yet, so they can be changed if need be. I'm also going to be the party face, so I took proficiency in deception, insight, intimidation, and persuasion; however, it's going to be a more combat focused campaign, so I'm not sure how often that will come up.

Thanks for the advice.

Your character is nearly identical to mine (edit: I have a 16 INT, but less CON and DEX(, albeit I'm now 7th level. EB is critical, but if you're going support, for combat you want illusion and board control spells, and socially charms and the like. From an arcane research perspective, getting things like Eldritch Sight invocation is really good. I know people say it's a Ritual, but having it always available - particularly in a magic-heavy world - is useful. I also had Eyes of the Runekeeper, which I kept until the DM allowed me to write it into my Grimoire as a ritual. 

Agonizing blast is fine, but if you find yourself only supporting others who score kills, you may want to consider repelling blast instead. This increases your effectiveness in board control. In concert with a feat like spell sniper, you can get off several hits, move enemies around the board and help set them up for a kill, even if you're not doing a ton of damage.

Spell wise, I love armor of Agathys. That'll up your survivability while you Eldritch blast your way through combat. Ray of Frost is also really good, not for the damage, but the debuff. Faerie fire is also a good combat support spell.

Friends and minor illusion are also nice, though the usual warning with charms: they piss people off once they realize they've been charmed. 

Good luck!

First off, you should swap dex and con. You want to be able to be good at dodging, rather than take hits yourself. I would say take minor illusion, prestidigitation and maybe eldritch blast. If not, just take something like control flames or create bonfire. They can all be used to trick opponents and get yourself out of tight situations. I might be tempted to take fey step instead of cantrip for the half elf. You can get in and out of combat easily. And it resets on a short rest, which you should be taking lots for spell slots. Lvl 1 spells: hex, cause fear, charm person, faerie fire is a MUST. Helps everyone. Expeditious retreat. I would probably say faerie fire and armour of agathys. 

Thanks for the help. I took the cantrips eldritch blast, prestidigitation, and chill touch; I took hex and faerie fire as my 1st level spells. I also switched around dex and con. Repelling blast might be better, but as the other members of the party are a frontline rouge and (soon to be spore) druid they'll both most likely be fighting up front, so pushing people back isn't very useful. Thanks for the advice you two.

You're welcome. I wish you success!

Your party have any pure casters or combat types?

So far we're my archfey warlock, a druid, and a rouge all at level one.

Quote from 20kernsd >>

So far we're my archfey warlock, a druid, and a rouge all at level one.

 Ok, so you have 3 very flexible classes, but lack for a pure physical type (fighter, paladin, UA ranger, barbarian) and a pure caster (wizard, sorcerer). If you're going as a power trio, you'll want to figure out roles in combat. 

Druid is going for spore, so he can be tanky and deal damage. I'm going support. The rouge is most likely going for the assassin subclass, so he's going for good DPR.

Just changed up some of my stats using point buy. I now have a STR: 8 DEX: 14 CON: 14 INT: 10 WIS: 14 CHA: 16. I'm going to multiclass into druid or cleric at some point for the medium armor proficiency, which is why I lowered my dex. Any suggestions on which to multiclass into? I also changed from high half-elf to regular half-elf to pick up proficiency in performance and stealth.

I would consider picking the Magic Initiate feat and not worrying too much about medium armor. Warlocks can stay out of melee easily enough that your more in danger from spells and ranged attacks, and an Archfey warlock can use Misty Step and Fey Presence once each per short rest. Plus you can combine the Minor Illusion cantrip and the Misty Visions invocation to create incredible illusions if you’re creative enough. I used them to create a “mud elemental” who rose out of muddy earth with a slurping sound and swiped at a PC when I was the DM once and I kept half of the party occupied for 2 rounds with it before they realized that it was an illusion. 2 rounds is a long time in melee combat.

Physical interaction with the image reveals it to be an illusion, because things can pass through it.

Because of that one line in both of the spells that wouldn't work by RAW. It would be cool if allowed, but I'd prefer to have a build that works within RAW just in case the DM doesn't allow it. Also, as I DM a lot, I know that I allow pretty much anything within reason as long as the players don't abuse it and that would be a gimmick you'd have to abuse to keep up as it takes up a cantrip and an invocation, so if the DM decides to disallow it because of how much I'm using it I'd have wasted a cantrip and invocation. 

I personally think Mask of Many Faces fits an Archfey warlock to a T. Very tricksy for infiltration, getting lost in a crowd, and mind games. Super fae.

You can also use Misty Visions to pull of an early prototype of the the Devil's Sight + Darkness combo. Just summon an illusion of something Large like ... I dunno, a Beholder ... on top of yourself. Now your enemies can't see you, but because you know it is an illusion you can see through it and thus you get Advantage on your Eldritch Blast attacks.

If you're going normal half elf, then you'll only have 2 cantrips. So I would say get rid of prestidigitation. 

It works for a couple of rounds. Longer if the party doesn’t talk and the first one who hits it with a weapon doesn’t tell the rest that it’s an illusion. But you’re correct, that particular illusion only works until an opponent interacts with it. It was still great fun for two rounds!

Quote from gabrielrockman >>

An illusion doesn't have any AC, so any attempt to attack it will make it clear that it is an illusion.  And anyone that can see the attempt to attack it will recognize that it is an illusion because they will see the attack pass through it.  There's no way that it should have lasted two rounds as a distraction.  

Silent Image and Minor Illusion are great at providing cover, but if you attack through them, they're revealed as illusions.  If you're using them as cover, you have to make sure that you go outside of their illusion of cover to do your attack unless you want to reveal to the enemy that your cover is just an illusion.

I don't agree. If you choose the illusion of something that could realistically shoot rays, like a beholder, then I don't see why it would be revealed as an illusion if you shot your Eldritch Blast through it. Or if you picked something that could realistically allow things to pass through it, like fog.

A Silent Image of a big bloof of fog - or sudden profusion of tall grass, or any other "concealment-not-cover" form of obscurement - is realistically no different than a regular Fog spell...save that you can see through it because you know it's not real.

ANYWAYS.  Been hesitant to comment in this thread because the OP is looking for specific build advice, but man.  It sucks to see so many people Feylock so weirdly.  T_T

The Archfey patron abilities for the warlock, most notably its ESL and its first two specialist abilities, are designed for indirect action.  The Archfey warlock excels as either a social butterfly/peoplemancer (note that Fey Presence is a charm effect that does not anger the target, nor is it something that explicitly states the target is aware of being manipulated - you just get really freaking pretty for a second and the target(s) go "wow...", while you gain advantage on a key Charisma check), or as a magical thief and infiltrator.  Archfey warlocks excel at getting people to do (or not do) what they want, and at getting into places they're not supposed to be.  They're not combat medics, they're not Buff Bois, and they're not combat monsters.  What they are is sneaky, tricksy jerks that pair well with a devious player without giving up combat capability.

You can avoid playing into this, of course.  Do what you will, especially if you're in a limited party and you need to fill multiple roles.  But be aware that warlocks in general are not usually good at "Support".  Book of Ancient Secrets can make you excellent for utility, but utility is distinctly different than support.  If you want to be The Combat Buff Guy who makes your allies super awesome at killing stuff, just about the only option you have for that is Faerie Fire.  Now, Faerie Fire is an excellent spell, but your druid is better at using it than you are because the druid has the spell slots to spare for it.  If you want to be the problem-solving Utility Monkey instead, prioritize manipulation spells and filling your Book of Shadows with every ritual you can find.

Thanks for the advice everyone. I do see that feylock isn't the best for buffs and is more about social trickery and I will utilize that quite a bit, but it's going to be a more combat focused campaign, so I have to balance that out with some good utility or buffs and debuffs, so I'm useful to the party in combat. I fully realize that I'm going to be weaker than the party in combat, but I don't want to be completely useless. I also have no idea how to build an effective warlock since this is my first time playing one, and most of the guides/builds for warlock I found were for other subclasses. There's also the problem of short rests, because every other party member gets nothing but hp back on short rests they're not going to want to take short rests unless we're badly injured. That makes my build even less effective. I know personally as a DM that I try to not give short rests in the middle of dungeons or combats because it allows players to get back hp and makes every other encounter going forward easier because of that. 

Tell your party to suck it up and let you have short rests when you need them, because that's a key feature of your class.

That said?  Eldritch Blast + Agonizing Blast, by itself, will suffice for your combat needs most of the time.  That spell with that Invocation is one of the best 'weapons' in the game, dealing a d10+CHA damage and gaining extra attacks at the same or better rate a martial class does.  Agonizing Blast will by itself allow you to outdamage the Spore druid and keep up decently well with the rogue outside crit damage.

If you want cool spells to help you fight, beyond just Hex?  Spider Climb lets you maneuver pretty freely in a dungeon and take up advantageous spots.  It's also quite useful for getting into funky places and lasts a lot longer than Fly.  Hypnotic Pattern, at 3rd, can end a fight if the critters hit by it all roll badly.  Shadow of Moil, at 4th, heavily obscures you, which means all of your Eldritch Blast bolts are fired at advantage.  Greater Invisibility, at 4th level from the Archfey list, does much the same thing save without the grandiose Shadow Man posturing.

Warlocks can fight perfectly fine, with or without Hex.  Archfey is not the fighty expert, but the base warlock class itself is a perfectly capable combatant.