I agree with the local club suggestion.
There are several trails I know of near you that are great and not very difficult. Near Harrisonburg, Va is the Rocky Run OHV area. It's part of the George Washington National Forest. A little further north near Endinburg, Va is Peter's Mill Run which is also part of GWNF. In western Maryland is Greenridge State forest which is near Flintstone, Md. All three of these are mild with lots of rocks and at times, a lot of mud. I have heard of a few others further south on I-81 but haven't been to those as of yet.
There are others such as Gore, Va and Crozet, Va that have more challenging trails but I believe you need to be associated with a club to gain access to these areas.