It will actually depend on which species you choose. Some or more active, some are teeny tiny, etc. If you'd like, you can research them and post which you are most interested in. I'd be happy to help you determine if they go together well and how many of each you can have. I'll also list some examples of good stock lists:
6 ember tetra OR microdevario kubotai
2-3 sparkling gourami OR scarlet badis
10 chili rasboras
5 male endlers livebearers OR norman's lampeye
8 least killies
5 pygmy sunfish
^ no heater needed for this stock
6 CPD's OR danio erythromicron OR danio tiniwini
6 hara jerdoni
^ no heater for this tank, the hara's need cooler water, keep in an area that won't exceed around 75 degrees. A sandy substrate is needed for them as well.
6 CPD's OR danio erythromicron OR danio tiniwini
CPO's or cajuns - you could start with 1-2 pairs of either of these as they will reproduce for you.
^ no heater needed for this stock
You could try dwarf shrimp in any of these set ups as well. I'm not saying any of these numbers have to be exact, except for those that are schoolers do need atleast 6, but some good overall examples.