Sculpin are actually pretty easy to keep as long as you have a well oxygenated, cycled tank and clean it regularly. A polluted tank is their main killer, so don't be scared of water changes.
You want a tank that's below the mid 70s (it doesn't need to be an extremely cold tank as some suggest, though that will prolong their lifespan some), so put it in a cool room with no heater. If you let your house get hot in the summer and don't run A/C for instance you probably aren't going to have good luck, but otherwise you should be fine.
Some sculpins don't want to eat anything but live food at first, especially the larger ones. I suggest catching the smallest ones possible, while still being large enough that they will be able to fit what you can get for them (they can swallow food up to about 1/4-1/3 their size) because the smaller ones seem to take to prepared food easier. My current mottled sculpins actually took to frozen glassworms immediately and I didn't even have to feed them anything live. But you should always be prepared to feed live foods such as small fish, or worms, just in case.
At best you will have to start out with frozen foods, and you will likely have to try a variety to see what they like (I suggest the frozen glassworms, and/or bloodworms, and any foods should be as fresh as possible), as they will most likely completely ignore flake or pellets.
