As a through-and-through single, I can't speak highly enough for the SCCampers group and their friendship. it's a very mixed group & I've had a blast on every trip. As Evie said, it's sometimes nice to be attached to something, but yet have the freedom to be independent. I like knowing that I'm known by someone else in another rig in the campground.
That said, I've taken 1 BIG trip in my trailer by myself (1600 mi.). I enjoyed it, but honestly found myself not doing things I would have if I'd had someone else along with me. In one particular place it was very, very remote and I didn't feel comfortable (safe) tromping around by myself. On the other hand, when I was in Monterey (Calif.) and knew the town well I had a blast.
I think you know what you feel comfortable with in life. The same holds true for camping. If you've got friends who'll go with you on weekends I think you'll find it really enjoyable. As far as groups, don't be afraid to check out a few, just to see what fit.
I'm rambling ... ;)
In terms of trailer/rig, I've got a 19' hybrid. Started out in a pop-up but found that I wanted the ability to stop at a WalMart parking lot overnight without having to set up. I like a trailer because I want to be able to go places out side the campground. What you get obviously depends on your finances and your tow vehicle, if you decide to pull something.
Start looking at everything! You'll have a blast! And welcome!
Laura -- and Jed