The championships you need for this can be accessed by going to Free Play on the main menu and selecting Historic. If you're going for these achievements:
you will get this one along the way, but completing any 3 historic championships will do. You do not have to win the championships to get this achievement, only complete them, but you must complete all events in the championship for it to count. Retiring because your vehicle is too damaged to continue will not count. Assists and AI difficulty do not matter so set those however you want.