If you're still learning how to dress better, it can help to have some "cheat sheets" on hand. This graphic from Slaters shows you what colour shoes go with what colour suits.
Of course, fashion rules were made to be broken, but if you're just getting the hang of things, this very basic guide should help you stay on track. Black shoes go with just about anything, but if you want to stand out, a light or dark brown shoe with a navy, blue, or light grey suit can look great. Print it out, pin it up in your closet, and you'll always match them up correctly. (Just don't wear them with white socks.)