Usually need more than one catfish...
Most catfish like to be with others of their type, 4-5 as a minimum. They hang out together and spin yarns about us fishkeepers. They also lay eggs from time to time, my own about once a week, others faster than that. But they also eat the eggs, so no problem there, unless you want to raise catfish. It is very difficult to tell them apart unless you look down on them and see that the female is much wider than the males, because she is making eggs and needs more space for them. When young, forget it, just take whatever is available... I feed my cats the TetraVeggie Extreme Algae Wafers which sink right away. If they are small, you can use the Hikari Tropical Mini Algae Wafers which also sink.
Good luck with your tank and whatever catfish you add to it!