I'd start with ghost shrimp, and once you can keep them alive (they are by far cheaper) I'd move up to cherries. I'm fixing to get some cherries soon! Shrimp are picky about water so it's not good to put them in a new tank. Ghost shrimp, some of them anyway won't breed in fresh water but they're a good starter shrimp. They are also super picky with medications, so don't medicate tanks with shrimp in them. Avoid foods with copper. And if a fish is big enough to fit it in it's mouth...it will be eaten. They will appreciate hidey holes/ caves, and fluffy little plants like java moss or hornwort.