They have a completely different diet so that would be tricky. Live worms would be my first choice to attempt catching both on the same bait. Corn, bread, and sweet stuff like mulberry paste or oatmeal is what carp like. They are one of the few fish in America that routinely eat carbohydrates. Catfish are predators and eat mostly other fish but have been known to take anything. I catch most of my catfish with small shad, cut up herring, or bluegill in any capacity. Where to find catfish depends on time of year, although shallow water is pretty good where I live year round. If there are schools of shad around, there are catfish near by. Lately I have caught them on 6-10 feet deep mud flats as well as suspended over 50 feet of water near bridge posts