You have some options. Some examples are:
-- 6-8 nano fish like ember tetra, chili rasbora or celestial pearl danio. Unfortunately nano fish can be hard to find locally (I bought my CPD from a breeder online). Most tetras, danios and rasboras are too active for a 10 gal but nano fish would work; just be sure they are truly nano fish. Neon tetras for example are small but very active and would prefer a larger tank (although some disagree) and aren't truly nano fish. You could also do 1-2 scarlet badis (again not easy to find) and maybe 4 pygmy or dwarf cory (again corys are debatable in a small tank due to their activity level. Pygmy or dwarfs are the smallest ones, don't get any of the larger types, but again they can be hard to find). OR
-- a single betta (very entertaining, I love mine). You can add some shrimp or snails or even the corys if the betta tolerates them (some tolerate tank mates, some won't) OR
-- 3-4 guppies OR
-- 2-3 platy OR
-- 3 african dwarf frogs OR
-- 2 dwarf puffers
There are other options, those are just a few.