that would be a pleco, looks like one of the 'common' species. hope you have a big tank, depending on what species it is, it'll reach 18-24 inches or longer.
Looks like a common pleco to me. None of the distinct color patterns of fancy ones. You could check mouth to see if it's a rubberlip pleco, but I doubt it.
It does look like one of the common plecos- but you don't normally see them in aquarium shops less than 3" long, and that little fella looks a good bit smaller?
If it is a "common pleco", it could be Hypostomus and reach about 8", or Liposarchus and reach 2'!
Thank you for all the responses! I've been told the best things to feed them are lettuce/zucchini/squash and veggies like that.. are those the best things I can give him?
Those are all very good for him, but at his size, you can maintain him on algae wafers and the occasional shrimp pellet till he grows a little. Some driftwood for him to scrub on would also be good.
He will also eat "normal" aquarium fish food- flake, frozen bloodworm etc.- just make sure he gets some vegetable matter as a supplement. My baby Ancsistrus and the sailfin plec forget all about veggies when there's frozen bloodworm to be fought over!