Help with Warlock spells

[Sirris]

I'm currently building a buff-debuff//battlefield control Archfey tomelock. I'll probably only be attacking with EB and the rest will be support.

Though I'm not sure which spells I should pick exactly.

I'm in a party with a barbarian, a cleric and a druid.
We'll be starting at level 1.
Planned invocations: Agonizing Blast, Book of Ancient Secrets, Beguiling Influence. (later: Devil's Sight, Repelling Blast)

Thanks for any help!

[Mandragola]

Well you'll want hex.

Sleep is generally seen as the best control spell at level 1. It gets less good as you level up, but a warlock does keep casting it at the highest level possible.

I'm AFB at the moment so I'm not sure about 2nd. Suggestion and web are good options - web especially since so many control spells target wisdom, so this is good against wise but puny enemies.

At 3rd level the most important spell is probably counterspell.

[Joe the Rat]

I'd tell you to go repelling first (pushing is fun!), but it looks like you're the ranged damage guy.

Since you're going tome, consider the Vine Whip. Short range, but it can drag people back towards you (and the Barbarian). Get Spell Sniper, and you have a 60' range on that drag-back.
Your druid can Faerie Fire as well, but if they are disinclined to prep it, it's handy. Nothing else, you light up the room a little.
Hold Person, when it sticks, is murder.
For 3rd, Hypnotic Pattern is another good wisdom-blaster, but I cannot say enough nice things about Black Tentacles Jr. Hunger of Hadar. It is not a strong damage dealer, but it creates a rather large "Zone of Nope" you can use to reshape the field. Can't see in it, slows you down, it freezes you if you stay, it licks you if you move. You use it to force enemies to move in certain directions, or punish them if they decide to move around the scary barbarian. With Devil's Sight, you can still blast people in it. Use your cantrips and other spells to push/pull people back to the middle if they try to escape.

4th level: Banishment. Charisma(!!!) save to remove from the field.

Across the board, illusions can be used to confuse / mislead your opponents.

[Flashy]

4th level: Banishment. Charisma(!!!) save to remove from the field.

Just wanted to emphasize how excellent Banishment is, especially if you're playing a campaign with a fair number of outsiders.

[Sirris]

I'd tell you to go repelling first (pushing is fun!), but it looks like you're the ranged damage guy.

Since you're going tome, consider the Vine Whip. Short range, but it can drag people back towards you (and the Barbarian). Get Spell Sniper, and you have a 60' range on that drag-back.
Your druid can Faerie Fire as well, but if they are disinclined to prep it, it's handy. Nothing else, you light up the room a little.
Hold Person, when it sticks, is murder.
For 3rd, Hypnotic Pattern is another good wisdom-blaster, but I cannot say enough nice things about Black Tentacles Jr. Hunger of Hadar. It is not a strong damage dealer, but it creates a rather large "Zone of Nope" you can use to reshape the field. Can't see in it, slows you down, it freezes you if you stay, it licks you if you move. You use it to force enemies to move in certain directions, or punish them if they decide to move around the scary barbarian. With Devil's Sight, you can still blast people in it. Use your cantrips and other spells to push/pull people back to the middle if they try to escape.

4th level: Banishment. Charisma(!!!) save to remove from the field.

Across the board, illusions can be used to confuse / mislead your opponents.

Thanks again, great help :)

[CursedRhubarb]

1st level there aren't too many spells for control worth keeping too long. Highly recommended Hex but other than that, Sleep can be great but for the most part you'll get only one target with it so be careful using it with group since they can shake them awake and spoil plans. Comprehend Languages can be great out of combat. Useful for listening in but it's the second part where you can read any writing if you touch the surface it's on that makes it great.

2nd level spells is where it starts to get fun. Being a Feylock ypu can grab Calm Emotions for an AoE Cha save to make hostiles indifferent to your group. This can let you avoid dangerous fights or end ones when things start to go bad. Also great for if you get caught sneaking about. (Also completely shuts down enemy barbarians. Kinda hilarious to wait for them to rage them calm them)
Hold Person can be nasty with the auto crits for melee.your melee members will love this, careful on trying it on enemy clerics though since it's a Wis save.
Earthbind is great if you encounter a lot of flying enemies. Can deal nice damage with the fall and is a Str save.
Crown of Madness can be hilarious and fun but can be tricky to use, requires multiple enemies for max effect. Wis save.

3rd level spells, Hunger of Hadar is a big ol' bag of ***** to toss into a fight. Used strategically it can control enemy movement or be a nasty slow death. (Cast in a room and close the door and listen to them scream) terrifying to combine with agonizing blast, thorn whip (book invocation to get), and spell sniper to make thorn whip 60'. Odds are they won't ever get out for long since you can then push or pull them back into it. Just be careful of blinding friendlies. Dex save.
Hypnotic Pattern is awesome. Can shut down a group of enemies to deal with one at a time or if you don't damage them you can shut down a group then tie them up. Wis save.
Plant Growth can be fun. Force ground enemies to waste 20' movement for each 5' they go while group drops them from afar or while your group runs away. (Have druid cast this then HoH on it for extra fun). Also great way to make cash by doing the 8 hour cast for cash to boost farms. Kingdoms or towns will pay nicely or give items most times for it. If you've a base of operations this works wonders for growing stuff for potions and booze.

Going Tome pact there are a lot of awesome cantrips to pick from. Shillelagh will get you an awesome melee option for those times things get close and Thorn Whip is great for moving enemies or when guys get knocked prone. 30' (possibly 60') melee to avoid disadvantage with a 10' no save yank? Yes please. If Elemental Evil spells are allowed Mold Earth is great. Make shelter, create cover from ranged, dig out traps, bury those pesky corpses that seem to pile up on adventures, close off pathways to control enemy movement, or make climbing a lot easier. Imagination is key. Minor Illusion can be very useful as well. Guidance is also nice, unless your cleric grabs it, or you can both have it and guide two people.

Friends can be a fun cantrip to grab if you opt for the Mask of Many Faces invocation. Change your look, then use Friends so they get mad at whoever you looked like.

[BW022]

My advice...

A pure warlocks doesn't make a great buff-debuff//battlefield controller.

a) They lack the spells slots. They only get two or maybe three until 11th-level. They recharge on short rests, but rarely can you plan to cast more than one per combat and in many cases, you need to be able to go one or two combats without casting any spells.
b) Most spell slots tent to be spoken for. Typically, if you have two spell slots... one will be hex and one will often need to be a defensive spell.
c) When casting, they are almost always going to use their highest level spells -- and few buff/debuff/control spells scale well with slots.
d) The best control spell (darkness + devil's sight) tends to nerf the party and generally isn't used.
e) A lot of buff-debuff and control spells are concentration. Meaning, you can only have one.

My advice...

Consider starting with a level of cleric, sorcerer, or bard. All mean you have extra cantrips and two first level spell slots. These are big since you can fuel a few hexes a day without needing your high level spell slots. Both also give a good number of buff/debuff spells and healing. Cleric gives you armor (possibly heavy), shield, and domain abilities. It typically means a 13 or 14 wisdom. Bard gives you skills and bard song. Sorcerer, you might wait until 2nd, but it provides the slots and many spells scale well. You only need one level.