I love southern Utah and have been there five or six times. It is really an area that should be explored, not just driven through. For example, in the Escalante National Monument there is a road called the Burr Trail Road. It leads through a beautiful red rock canyon and even has a small slot canyon one can tour without hiking miles across the desert (as some of us older folks can no longer do). It is paved part of the way but changes to gravel when it crosses the border into Capitol Reef NP. If you are willing to drive the gravel you can go for many, many more miles.
Then there is Natural Bridges National Monument. The three natural bridges there are awesome. See them from road viewpoints or hike down the trails to get close-ups. Here's the Owachomo Bridge.
Camp and/or hike in the Kodachrome Basin State Park near Henrieville, just off UT12. Morning walks there are fantastic. Drive the Cottonwood Canyon Road and see the canyon and Grosvenor Arch (but I don' recommend pulling your TrailManor though there). There plenty of places for short walks or more ambitious hikes.
If you are able to hike and enjoy it, take the six-mile round trip up Calf Creek Canyon to beautiful Calf Creek Falls. It is well worth the time. Be prepared though, because the trail is soft sand all the way and this is more tiring than walking on a firm surface. The trail starts in the Calf Creek CG, just a few miles east of Escalante on UT12.
If you go to Bruce Canyon NP, consider staying at the Red Canyon CG instead of in the park. It's only about 10 miles from the park and has much nicer, bigger and more private campsites.
These are just a few of the lesser-known but fantastic places in Southern Utah.