So it's loosely modeled off of divine soul

LEVEL 1

FEY TONGUE: Speak and write Sylvan and get vicious mockery cantrip.

FEY MAGIC: gain access to Druid Spell list, you get Faerie Fire as a free spell and can spend 1 sorcery point while casting Faerie Fire to make it dispell magical darkness.

SELF PATRON (the replacement for favored by gods) you gain 1 warlock cantrip, 1 eldritch invocation, and whenever you would gain a metamagic option you may select an Eldritch invocation.  (I DON'T KNOW HOW TO IMPLEMENT THIS IN THE HOMEBREW SUBCLASS ON DNDBEYOND)

LEVEL 6

FAERIE GUIDE: you get a sprite familiar with essentially the upgrades from investments of the chain master and gift of the ever living ones.

LEVEL 14

FAIRY WINGS: essentially the level 14 ability from divine soul but they look like dragonfly or butterfly wings (your choice)

LEVEL 18

ARCHFEY FORM.  Your creature type becomes fey, you do not lose access to features with your previous creature type as a prerequisite but can not gain new features that requir you previous creature type. You do not age, you are immune to poison, and non magical disease. You gain advantage on all saving throws against magical effects.  You may spend 1 sorcery point while casting a spell that requires concentration to automatically succeed on all concentration  checks to maintain  the spell for its duration.  For 1 sorcery point you can step between the material plane and feywild.  While in the feywild you recover 1 sorcery point per round, to a maximum equal to your level, and you automaticall succeed on they retain your memory of your time in the feywild.

My questions are

1) is this overpowered?

2) how do I go about implementing Self Patron in the online character generator?

Sorry if this is late but there are a couple of bits for me that could do with improving. Firstly, Implementing stuff on online generators is probably impossible, they try but are just format the words you put in, not much more. Secondly, one sorcery point to go to the feywild, little bit OP let alone you go full coffeelock while there. Regaining sorcery points like that is just way too Op, why bother putting a cost to get there when they just make that 18 times in 5 minutes. Maybe once per short rest at a push, you could have some other stuff like bringing others with you. You should try implementing new and original features and i don't really understand the self patron, like do you worship yourself or what., like why do you have it. I get you implementing warlock stuff but i feel like it is a bit misguided. Overall though it has some great potential and is a really good idea.

The idea behind this subclass in general and self patron in particular is that you're a "baby archfey" who will grow up to become an archfey warlock patron (at some point past level 20) and before you can share the warlock powers with others you have to develop them in yourself.   It's not like you're worshipping yourself (although a baby archfey who knows they're going to grow up to be an archfey MIGHT BE that egotistical, as in a "my name is a holy name, blah, blah, blah" rant) or making a pact with yourself the point is you're innately manifesting warlock powers BECAUSE you are a baby archfey who is growing up (as in you didn't need to make a pact with some other entity to gain warlock powers).

Thanks for the suggestion to make stepping between the feywild and material plane a once per short rest ability.  And spend a sorcery point for each creature you bring with you save vs spell DC if they're unwilling.

My only concern about the once per short rest bit is that time passes differently in the feywild, so resting in the feywild doesn't mean much to an Archfey.  maybe a better requirement to step back is you must have 18 or more unspent sorcery points.  Might need to work up some short and long rest equivalent numbers of sorcery points.

Quote from EliasWindrider >>

The idea behind this subclass in general and self patron in particular is that you're a "baby archfey" who will grow up to become an archfey warlock patron (at some point past level 20) and before you can share the warlock powers with others you have to develop them in yourself.   It's not like you're worshipping yourself (although a baby archfey who knows they're going to grow up to be an archfey MIGHT BE that egotistical, as in a "my name is a holy name, blah, blah, blah" rant) or making a pact with yourself the point is you're innately manifesting warlock powers BECAUSE you are a baby archfey who is growing up (as in you didn't need to make a pact with some other entity to gain warlock powers).

Thanks for the suggestion to make stepping between the feywild and material plane a once per short rest ability.  And spend a sorcery point for each creature you bring with you save vs spell DC if they're unwilling.

My only concern about the once per short rest bit is that time passes differently in the feywild, so resting in the feywild doesn't mean much to an Archfey.  maybe a better requirement to step back is you must have 18 or more unspent sorcery points.  Might need to work up some short and long rest equivalent numbers of sorcery points.

 That clears things up and sounds like quite a fun idea with you being a baby arch fey. worth mentioning. a feature i recommend you give it is immunity to aging magical or normal, maybe disease as well. a sorcery point per person i think is reasonable and you should probably add a cap to no. of creatures you can bring. The issue I have with sorcery points is the same you have with a short rest, its okay once but if you start with low sorcery points then to get them back, you have to rest and as you said, resting in the fey wild is weird. Overall it sounds good, only a couple creases you might have to iron out.