if i have a college degree but has nothing to do with coaching football, do I need to certfied myself?

Answer 1

It depends on what state, or even sometimes the city that you live in and want to coach in.
It is a fairly simple process to become certified to coach.
You have to take and pass a class at a University or Community College. Then you are a certified coach. In a lot of areas that one certification will work for any sport.
Check with your state's or city's high school athletic association.

Answer 2

It depends where you are. Here you have to take a coaching class that is offered by the state in order to coach. I think it has more to do with the legality issues more than actually coaching.