I assume you have a Ford E450 chassis. We have a Sunseeker on a 2010 E450 that will turn 50,000 miles soon. I follow the "Special Operating Conditions" recommendations. I figure that hauling a motorhome coach is the same as towing all the time. I change the oil and filter every 5,000 miles, or once per year. It takes six quarts including what goes into the filter. I use full synthetic, but some on this forum use semi-synthetic. Both are recommended and it seems that either is okay.
Here's a link to download your Owner's Guide:
http://www.fordservicecontent.com/Fo...US_10_2015.pdf
The manual includes all models and applications for the entire E-series line, so it has a lot of information that doesn't apply to the Class C chassis that you have to wade through.
Look thoroughly through the Scheduled Maintenance section. You'll need to grease the steering linkage, change the transmission fluid and filter, and repack the front wheel bearings periodically. These tasks are seldom done on modern cars and pickups, so it's easy to forget about them. You need to change the coolant in five or six years, but you have lots of happy camping to do before that task. (It took four gallons of concentrated coolant.)
The tire shop told me that Michelin recommends rotating the tires every 5,000 miles, but I don't subscribe to that. If they are wearing equally I leave them alone. I have removed the wheels to check the brake pads a few times, so I went ahead and rotated the tires.
You need to look on this forum for threads about front end alignment. The Ford E450 invariably need realignment. The previous Forest River Class C sales manager had several posts about it. He said they seem to get out of line early but hold it after they have some miles. He recommended aligning it after 3,000 miles. You local Ford dealer may not have a bay or equipment large enough to do it. I had ours done at a local tire shop that specializes in trucks.
Don't be shy about posting your questions on this forum. Be sure to mention the brand name and model number of whatever you are asking about and you'll get a better response.
If you have problems on the road, post here with something like "Help - On the Road - XXX Doesn't Work" in the heading and you'll probably get a quick response.
Enjoy your new Sunseeker.