I got back into camping in a similar way. Starting with the trailer is good because you don't have to worry about a second drive train.
I do have two dogs that camp with me - that has countered two common issues with solo camping: loneliness/boredom and security. I often camp off season and alone or just one of two or three folks in the campground. I find I really enjoy that time and having the dogs ensures I have a hiking companion and a warning system.
General observations:
If you're single at home, camping is no different. You're more likely to find trouble in your own neighborhood than at a campground. So don't overstress about that. Just be observant and trust your spidey senses - if they tingle, leave.
For me, the joy of solo camping is that I am in control. I go when I want to go, rather than waiting for someone else to want to go. Now, I plan my camping trips and simply send the dates and locations to friends and say "if you want to join me, I'll be in site X". I plan my meals and most often have enough to share if someone does come out. Often someone will join for part of the trip and I'll be alone the other part. I've also invited folks to visit for a day if they live in the area - that works out well also.
Get yourself a basic toolkit to keep in the trailer. Things will go wrong with one thing or another. You'll get handy to fix the basics and will learn how to work around the rest. For example - battery power goes out and you can't get it working, use the campground water (you won't have a working water pump) and battery operated lanterns/flashlights; propane system stops working, use a cooler(I keep a soft-sided one in the closet) and cook on the fire; and so on. No reason for those things to end your trip.
As for driving the trailer, don't worry. Get some practice backing up at an empty parking lot and go for it. Going forward is not difficult at all.
I'm not one for the groups - I enjoy camping solo and am not trying to avoid it. If you prefer to have a "community" for support, the groups are good.
Start small - a two or three night trip. I have found that the small to medium sized campgrounds that are popular with fishermen, hikers, etc., are the best. There are usually folks there during my stay, but they don't bother me at all. They are polite and friendly but not intrusive.
Also, camp in your driveway as much as possible. Sleeping in the trailer in a familiar place will help you adjust to the trailer noises and any outside noises that come through. Then, when you go to a campground, you won't stress over every sound at night.
And most of all - ENJOY!!!!
1975 American Clipper RV with Dodge 360 (photo in profile)
1998 American Clipper Fold n Roll Folding Trailer
Both born in Morgan Hill, CA to Irv Perch (Daddy of the Aristocrat trailers)