Yeah, African Dwarf Frogs can live with fish
. The key is finding fish that are non-aggressive and can't fit in the frogs' mouths.
They do best on a varied diet of frozen/live meaty foods. My own frogs are fed bloodworms, brine shrimp, mysis shrimp, and krill. Pellets are fine as a supplement but I don't feel they should be the only thing fed.
African dwarf frogs, especially males, aren't always great at finding food. So you might have to use tweezers or a turkey baster to hand-feed or target-feed them. If your new frogs won't eat try frozen krill...that seems to be a favorite and very few frogs will turn it down. Live blackworms are another fave.
African dwarf frogs seem somewhat social and do best in small groups. So get at least two if possible. It's not necessary but they seem to enjoy hanging out with each other.
Be careful when buying your frogs and make sure you are getting the right species. Many petstores mix up African Dwarf Frogs and African Clawed Frogs. The latter get much bigger and will eat your fish. True African Dwarf Frogs do not come in albino and have webbed front and back feet. The Clawed Frogs do not have webbing on their front feet.
Be sure to provide African Dwarf Frogs with plenty of hiding spots...they love live plants and rock caves. Also be sure the filter current isn't very strong as they are poor swimmers. Unfortunately this means they can get caught in filters
. I don't even have a filter in my frog tank...the live plants and clam provide filteration
Oh, and I just noticed your last post. No, you can't keep them with goldfish. Goldfish are coldwater and african dwarves are tropical. They will be lethargic and sickly if kept in cold water. African dwarf frogs like temperatures in the mid to high 70's.