You're right, it's really easy to get lost there. Ringwood, Wawayanda and Allamuchy are are fairly vast and intersections start looking the same. I still get turned around the wrong way at RW and WSP, , and I've been riding there for years. and I still feel lost at the Mooch.
If you want to DIY, then I would start with some of the smaller parks that are easier to figure out. For example the Tourne is close to you and its a lot of fun, suitable for a beginner and not hard to find trails, and return to the car in a reasonable time!
Lewis Morris is another one that is really great for an adventurous beginner. Deer Park (south Allumuchy) and Kittatinny are others if you feel like traveling a little farther.
You can ride the cannonball trail at Ramapo and that is basically an out an back (you can even ride across 287 footbridge) so its not too hard to find your way back to the car.
If you want to link up with groups, the you might want to ring up a local bike shop that has regular group rides. For example I do know that Marty's does haveweekly rides
for beginners. I am sure there are other shops. That's where I would start anyway.
Maybe some others know of shop rides going on in No NJ? I don't know of any offhand, but there must be others.