How hard is it to get into the Air Force?

I slacked off in High school for the first two years but I have managed to change for the better. My Junior year i ped everything i needed to, Including the states (TAKs) test, My upcoming Senior year im going to p on time. Will the First two years effect me? I know the Military is becoming a resort to people due to the Economy, But i really want to be a Pararescue Jumper (Yes I know how hard it is) have been wanting to be one for a very long time. Do I just need to score the PJ ASVAB score? and get cleared through MEPS?