Sundadanio Axelrodi (there are green, Blue and red colors) would work, and Boraras Brigittae aka Chili Rasbora, and many others too which get on fine with lower pH. And other micro rasboras.
Clown Killifish, (Aplocheilus annulatus) Captive-Bred will eat prepared and frozen foods, wild caught like live foods and maybe frozen to thrive until if possible to train them to regular foods.
Bottom dwellers would be Dwarf Cories
Corydoras in Miniature
Check out Killies.
Some Caridina shrimp like Crystal Red aka CRS or Black aka CBS.
This is a nice resource - Rachel O'Leary is a force of learning and great person (and she is nice too!) to support for her helping so many people with their fish care and introducing the keeping of small fish to so many. Otherwise there is lots of no cost info available too, like here!