How big, exactly, the tank?
If you want groups of fish make sure you have at least a 10 gallon.
Which in case you can stock with the following options;
1 Male Honey Gourami, 6 Dwarf Rasboras, 4 Venezuelan Pygmy Corys
1 Male Sparkling Gourami, 2 Female Sparkling Gouramis, 4 Male Endler's Livebearers, 3 Venezuelan Pygmy Corys
1 Male Honey Gourami, 1 Female Honey Gourami, 4 Tail Spot Pygmy Cory, 4 Male Endler's Livebearers
6 Pygmy Hatchetfish, 5 Male Endler's Livebearers, 4 Venezuelan Pygmy Corys
1 Male Betta splenden, 6 Venezuelan Pygmy Corys
1 Male Dwarf Puffer, 2 Female Dwarf Puffers (or 3 females)
3 African Dwarf Frogs
Make sure to buy the tank and cycle it before getting any fish!!!