Well... I still think you should have done a bit more research. But we are here to help:
First of all: goldfish should be by themselves. I see you mixed in some other fish (chinese danio's)? I would strongly suggest against it. Goldfish are really dirty and messy fish.
Secondly: goldfish should not be housed in a 40g. I know these are not common goldfish, but they'll still grow to decent size.
Easy plants are anubias, java fern, echinodorus species, crypts etc.
Sent per three-eyed raven..