We only stopped for one night in Moab/Arches. It was a great place for a layover between Breckenridge, CO and Bryce, UT. We arrived early enough to spend a few hours in Arches National Park. For me, this was more than enough as my eyes become visually over stimulated. Spend an extra day or two here if you want to explore more.
Arches is located in Eastern Utah(adjacent to the Colorado River and 4 miles north of Moab, Utah). Wind, water and underground salt beds have created the most incredible monuments. Definitely a must see. After you see it you will be left saying to yourself " What did I just see?"
Cost to get into the park is $10 per car but with a National Park Disabled access pass, the fee is waived. You can view much of the park from your vehicle. A few scenic locations have wheelchair accessible trails to view even more spectacular sights. There is so much to look at and the road is constantly turning, so if you're prone to motion sickness be prepared. There are several designated stops along the way to take beautiful pictures. Other activities in the park include hiking, biking, backpacking and climbing. My recommendation is visiting in the spring or fall because summer temperatures can become quite brutal.
I do not have an RV park to recommend. The place we stayed at is going out of business. There were a few other RV Parks in the area to choose from.
Another fun thing to do in this area is shopping and eating. The city of Moab, Utah is flat with tons of shops, restaurants and bars to choose from. We ate at, La Hacienda. It was really good!