I saw on another thread that you said you were going to do one betta, one Julii cory, and one Molly.
Is that still your plan or have you reconsidered?
Because the really honest truth is that a Molly has a large bioload and needs 20 gallons, and the cory needs a group of 3 at the very very least, 5 being ideal, and shouldn't be kept in anything smaller than 15 gallons imo
I think a good idea would be 1 betta and 5 shrimp. Shrimp are actually so fun to watch.