^^Would need 30 gallons, dude
White Clouds, but theyre jumpers and messy eaters. DO NOT overfeed.
Mosquitofish are nice, you could probably catch em, but all females OR all males or you wont know what to do with them.
Guppies (wild varieties from feeder tanks are real lookers, but find out which day the LFS stocks them and buy the following day so you dont get any fish that have been exposed to feeder diseases.
Ghost Shrimp, I wouldnt suggest Snails because newbie aquarists will not be satisfied with Snails.
Small natives, such as Fathead Minnows.