Yes. Painting the outside of a camper van is very similar to painting any vehicle. Fortunately, though, the finish is a bit more forgiving than on a passenger car.
The most important step is to thoroughly clean the RV (a power washer works well for this project).
Use an automotive-grade formula in your chosen color. While you can use a brush and roller, a sprayer will make quick work of your RV’s new paint job.