All the trails inside the Sand Flats Recreation Area would be fine solo since there will be tons of other people around.
Top of the world was also a fun trail (and a forum favorite for the ride of the month photos). We saw a decent amount of people there so I wouldn't really worry about getting stranded. The first part is very easy. Towards the end of the trail, it gets more difficult but not bad if you take your time (2-3 foot climbs).
Red rock 4-wheelers rates all the trails on their site linked below. When we were there we stuck with 6 rated trails. That said we never needed a winch and nobody got stuck. (It rained a few days on us so we likely had even less traction on some of the trails)
https://www.rr4w.com/Trails-Home.cfm
Poison spider was one of my favorites. - It only had 1 tricky bit but if you choose a smart line you'd likely cruise up it.
@JMT , my FIL, and I cruised over to elephant hill also. The scenery was awesome and you can do plenty of hikes in the area. *You need to reserve a spot for the trail 24hrs beforehand and if you get stuck you'll need to pay a 1,000 fine to get towed out.
That said the first section is the only difficult part and by the looks of your jeep you should cruise right up it.
Welcome to the forum BTW from a fellow Norcal jeeper.