You should check every square inch of the exterior surfaces of your RV a couple of times a year. If your RV was built well you should rarely find an issue. The most common might be some areas where the caulk is starting to fail. Typically the issues are on the roof and the repair is easy. Remove any loose caulk, clean the area with soap and water and then with mineral spirits. Recaulk.
Washing and waxing is entirely different and is mainly a cosmetic issue. Wax will help prevent oxidation and will prolong the shiny appearance. After spending long hours with conventional waxes, I quit that activity and switched to Zep acrylic floor finish. Application is simple. Wipe on a thin layer onto a clean RV. Repeat with about 4 coats. You can use a long handled sponge applicator. I prefer to use a ladder and a rag lightly dampened with Zep. Once completed the finish will last for years. The only exception might be the nose of the RV. I often travel for months and dried on bugs can be difficult to remove. Last trip I stripped the wax off the nose of the RV and reapplied. The rest of the RV looks great after 2 years without maintenance. I especially like that the black streak issue I previously had is gone.
The previous post is wrong. There is a "magic" solution to exterior maintenance.