How often do I need to feed fish?

I just sold my aquarium and I'm enjoying not having to feed the fish
2-3 times a day.
But now I'm planning a small raised pond (100gal) and I'm thinking I
will need to have a few fish to eat mosquito larvae and provide
entertainment (a couple of goldfish would be nice to look at). On the
other hand, I don't want to go back to daily feeding.
Anyone have reccomendations, as to what fish would be good for the
above purposes (especially mosquitoes) but that would require minimal
feeding? Is there something I can add (e.g. plants) that will provide
food?
If it matters, our winters are mild in central Texas, but we do have
long summers.
Thanks,
Sam