When I joined the Army I had never done any significant running. You need to run, jog, and stretch, then run some more. You being able to pass the running portion of BCT will be an advantage to you. Run and stretch.. do a lot of stretching. But most importantly start as soon as you can. You want to build your endurance so a gradual is ideal. Run 0.25 miles for 3 days then 0.5 miles for 5 days, then 1 mile, then 1.5 then 2. I would practice running 2.5 until you leave for BCT. I would also make sure you can do about 30 push up and 60 sit ups. Good Luck, and remember that nothing good comes easy.