@Uberland, how are ya? Definitely stay in touch with this thread and the Rally Points. Anything that's an official calling for a day trip, weekend event, etc will get posted. As
@geekyadam and
@NovaBound mentioned, they do end up being very impromptu at times, simply due to everyone's schedules.
Now, to answer your question for a local /weekend trip. Yes....head out to Peters Mill Run, just west of Front Royal by about 20 minutes, in an area called Fort Valley. It's a designated, legal off road trail system that runs through the George Washington National Forest. It's not technical at all, but it is rocky. You will have zero problems in your rig, and won't need a spotter. You will need to purchase a pass to enjoy the trails. Grab a pass at the Fort Valley Country Store on Fort Valley Rd. They're $5 for the whole day. You'll come across a few other vehicles, and probably numerous motorcycles and ATV's. There's generally enough room for everyone to pass each other safely. There's a couple of spots where it does get tight, but you'll be fine.
In that same vicinity there's tons of Forest Roads with dispersed camping as well. There's also Elizabeth Furnace Campground, and Camp Roosevelt, both off of Fort Valley Road. You also have Little Fort Campground directly next to Peters Mill Run-a small'ish campground, generally pretty packed on the weekends, as it only has about a dozen sites.
There will probably be a weekend trip coming up fairly soon out to that area, which will get posted here.