How many fish can you put in a 2 gallon aquarium?

It really depends on the kind and size of the fish. A single betta (Siamese fighter fish) is probably your best bet, because they aren't that messy, don't need a lot of room, and can breath air. Goldfish, on the other hand, grow very large and are very messy. You could probably fit one or two small feeders for now, but not for very long at all, and you'd have to clean the tank pretty often. Another good choice would be a pair of guppies or platys. Be careful, though, they can also be a bit messy, and they tend to breed like rabbits. Basically, just do some research on the fish before you buy them. A baby angelfish the size of a dime will be alright for a little while, but he'll grow to a good 6 inches before long.