Goldfish have a tendency to eat most plants. This is why most goldfish tanks are baren or use fake plants. If their diet is not complete otherwise they usually need plants to hlep complete it. Mine don't eat any plants except for duckweed, I feed New Life Spectrum. The usual food plants are cheaper stuff like anacharis.
Mine will eat duckweed, hornwort, anacharis. All are fast growers that will use up some of the nitrates. Duckweed is goldfish candy
You can usually find hornwort and anacharis as pond plants; a better value then as aquarium plants (bigger bunch for same $$).
If the GF are small, anacharis may get chewed up and spit back out, in my experience...no biggie but unsightly.
I have Java ferns, amazon swords and anubias in my goldfish tank. They don't touch them.