I Am 13 years old and foot bal starts for me(middle school) in 2 weeks. can anyone tell me what to do?

You really should have contacted the physical education department at the end of your last school year and shown interest then, but it is not too late to be a "walk on". Contact the department soonest in order to get details and instruction and continue to practice and train on your own and with others until practice starts. Don't miss practice and show lots of spirit and determination. Good luck.