I don't know about New Jersey since I don't live there. But the best thing you can do is start preparing yourself by taking training. Start with an NRA Basic Pistol course (they'll provide the guns), then work your way up as far as you can afford. A short drive to Connecticut will allow you to take advantage of training from Mas Ayoob and Chuck Taylor, for example, through Defense Associates (www.defenseassociates.com). You can likely get a loaner gun for the classes if you ask.
I believe there are also good trainers in New York, and there used to be a very active defense-oriented club on Long Island, and it may still be active. Pine Barrens, maybe?
It's never too early to start training. I took my first formal training twenty years ago when I was 16, through the aforementioned Defense Associates, and have pursued training ever since. It has served me well.