If you're worried about the physical training, start preparing now. Get into a good fitness routine and start running. Nothing hard core but if you can manage 2 miles in under 15 minutes before you start basic training, you'll be well ahead of the curve. (and your running shoes will be well broken-in - that means you need to buy a quality pair of running shoes now if you can at all afford it. Make it a priority item.)
Working on pushups and situps would be an excellent idea, too. If you start spending a half hour per day on your own with a couple of months to go before you leave, you'll find the pace in basic training very easy.
And if you smoke, stop now. Quit on your own instead of having it forced on you while you're under a lot of additional stress later.
If you get started now, you'll breeze through basic with ease. Don't sweat the rest of it. Just keep your mouth shut and your eyes and ears open and pay attention and do what you're told and it will be over before you know it.