Welcome to MFK!!!
If at all possible, keep the paddlefish in a round vessel. These fish just beat themselves to death in a rectangular tank. Curved walls help them 'ride out' a ramming.
Keep the paddlefish in an unheated tank with lots of water movement and tons of aeration. They're filter-feeders but once they pass a foot in length, they'll have no problem taking down the occassional rosy red minnow or two. Mine fed on FD plankton/krill, frozen daphnia, flake food, bloodworms, etc. Basically, they'll eat anything suspended in the water column or on the surface. It took my 4 inchers only about a week to learn to roll over to get at floating food.
They're scaleless except for a few patches of dermal denticles. So, adding some salt to their water will help keep fungal infections down. I kept their water on the alkaline side and they were just fine with it.