I have a gelcoat exterior. I was given my initial trailer care kit by the dealer and it included a gelcoat polish after using an RV cleaner. Wow, that's a lot of work!
Find out what kind of exterior your camper has and use something appropriate. You'll also need to know if you can use the same thing for decals and graphics since many times these are NOT painted and using the wrong stuff can create problems. My trailer is more of a pain to clean and keep clean as my vehicles since car care is so much more popular and known.