ccotenj, here are the boards of several clubs in the NJ/Pa area that periodically wheel at Paragon (Hazelton, PA) or Rausch Creek (Tremont, Pa):
http://bb.njax.net/ http://www.niora4x4club.com/phpBB2/index.php http://www.xterrafirma.com/ http://fat4x4.com/bulletin/index.php http://forum.ne4wd.org/ http://christiancrawlers.org/phpBB/index.php Some of the clubs/boards are more active than others. Just keep an eye open on the boards, and come on out. Any of these groups will be more than glad to help out a new comer.
However, keep in mind that for Xterra people, there may not be much activity until after ECXC, a four day event in July, because (a) they are busy preparing their trucks for the event, or (b) they don't want to risk damage before the event. Things may pick up a bit in August/Sept.
k_enn
PS, what you learned in "street driving" school has little to do with off-roading. I used to run a lot of autocrossing in SCCA and similar street driving in my old porsche, and virtually none of that carries over into off-roading (other than avoiding quickly upsetting the balancing of the vehicle and perhaps heal-and-toe technique if you drive a stick).
[PS added and typos corrected]