First off, congrats! Second off, a little advice to consider: Try to get a "guaranteed contract." That is, if your test scores are high enough, get it in writing that you will get a technical billet. (Billet = position). To quote my dad, "Do something that you can use after you get out." It will also make it easier for your parents to sign for you since you need their signatures if you're still 17 when you enlist.
I signed my papers on my 17th birthday in Dec of (doing the math...) 1982 (holy crap), and spent 7 months in the Delayed Entry Pool/Program. We had monthly "Pooly Meets" and went rappelling, did some shooting, etc. It was great fun.
It's all a great adventure, too, to be sure. You'll never forget it for the rest of your life. Best of luck to you!