I've never had call ducks, but have read that they need an enclosed pen since they are so small and fly alot. If they are anything like my ducks they can eat chicken food at adults but babies need flock raiser or to be supplemented wit niacin to prevent leg issues. You also have to be prepared for the mess, ducks are very messing with their water from day 1.
My daughter raises call ducks. They are very easy and they eat the same stuff chickens eat. The female can be very loud she will let you know when something different is around. We enjoy them they are sweet. Good luck