I recommend no other fish tank mates unless 10g+. Under 10 shrimp or snails will work. For a 10 gallon you could do a small group of Pygmy cories, or chili rasboras or endlers. Maybe a few female guppies. Then 20 gallon + you have a lot more options.
20 long- school of harlequin rasboras (7) school of albino corydoras (7)
Otto cat (1) ghost shrimp (2) male betta (1) filter is for a 50 gallon tank,
and it is heavily planted.
Fluval spec v – male betta (1) nerite snail (1) ghost shrimp (1) plants.