I play in a softball league. We practice once a week and have at least one game a week. Should I count that as my cardio for the week?

That definitely sounds like a great way to get cardio in - way to go! If you feel like you need additional cardio, it wouldn't hurt to throw another session in there somewhere during the week, but if you feel like softball is a good amount of cardio for you, I don't see any reason to do extra.