Well first off what is your room temperature? My suggestion with such a small tank would be maybe a few amano shrimp and a couple olive Nerite or horned Nerite snails and run an azoo palm filter or small sponge filter. Maybe put some petite anubias and some sort of moss (java moss, Christmas moss). I'm no expert but if I had a tank like that and just HAD to set it up and not upgrade to a larger tank that's the route I would take. Hopefully some more experienced members will chime in. From my research its hard to get a small tank like this cycled and have good water parameters for the inhabitants without stressing them out too much. May be more effort than its worth. Good luck!