If it is a Diesel many truck stops can do it, Prices may be excessive though. (oil change)
Some truck stops are near Blue Beacon or other truck wash places as well.
Camping World does oil changes and can wash it.
I do not knwo the mobile places near you.
On my gasser, the best deal I ever got on an oil change was an authorized service center,, Cost about the same as my car (It was a car dealer after all) 35 dollars les than CW.
MOST campgrounds will have either a business card or ad from a mobile RV servic e place on the cork board or members who can give you the name of a good one.
Washing is another matter.
I hope to be calling the local mobile tech.. Tomorrow. (She is holdign a part for me) .
Home is where I park it!