Went to 2 Trails when I visited the Mojave National Preserve.
Rings Loop Trail is an easy 1.5 hike that starts at the Hole in the Wall Visitor Center. If you’re working on a National Park Passport there is a stamp located inside the center.
Kelso Dunes can be easy or challenging depending on how far you go. There are no trails but the footprints are a good hint on where to go. I recommend going there later so you can catch the sunset (if you’re ambitious go during sunrise!). Bring a towel and find some shaded area to just take in the sights and sounds of the desert. Also have lots of water and a flashlight.
You can get more info here: