I would keep to two fish. So any of this would work
-Pair of clowns( some say a great begineer fish, but most are prone to ick, they have to been overbred way too much, kinda like the American Cocker Spaniel)
-Firefish(jumpers/passive)
-Shrimp goby and a pistol shrimp
-other small gobies
-blennys(can be aggressive)
-cardinal fish(passive)
-damsels(if you really want to go that route, and if you do I would only add damsels as other fish, and they might attack shrimp if you get some, not really recommended but some like them)
Their might be some more but those are the big nano fish
If I would you, I would go
-Pistol shrimp and hi fin red banded goby and firefish
-Pair of clowns
-Pistol shrimp and hi fin red banded goby and pajama cardinal
-Firefish, and some other small goby
