Congrats on the new coach. This is not the entire list of what I carry, but it might do for a started list.
1. 2 gallons (not quarts) of motor oil.
2. 2 gallons of antifreeze
3. 1 gallon of tranny fluid (the same that is in there now)
4. Extra filters:
4b. fuel water separator
5. a large variety of fuses. There are at least two different sizes of blade fuses maybe more. Check all you fuse locations to ensure a ready supply
6. rags/shop towels
7. basic set of tools (screw drivers, wrenches, etc.)
8. tire gage (I carry 3)
9. Consider joining a roadside emergency plan.
10. flashlights (I carry 4)
emergency roadside reflective triangles (set of 3)
11. portable battery charger
12. portable starting battery (mainly for the toad if there is a problem and we are away from the coach).
13. extra set of engine belts (a/c, alternator, etc.)
2005 Newmar KSDP 3910 + GMC ENVOY XUV 37K lbs Moving Down The Road
The Avatar Is Many Times Around The USA
Nobody Knows Your Coach Like Somebody Who Owns One Just Like Yours