Welcome! I am beginner too, and looking to find information on beginner trails. I checked out this link Trail Directory and it lists some beginner ones, but I want to hear some personal accounts and details, because they're always more a good perspective.
Having originated in Passaic Co myself, I now find home in Morris Co where there are a myriad of riding choices. The Tourne is nice. It gets harder the faster you go. Lewis Morris in Mo-Town also has a good mix beginner to intermediate.