There are several lists of tools necessary for a trailer camping trip on the web.
I carry spare RV sewer caps, bulbs, fuses, vice grips, small level, hammer, asst. screw drivers, wrench set,duct and
electrical tapes.
I also use a BAL
Light Trailer Tire Leveler - so much easier to level the trailer. They'll add @19 lbs to your gear, but also work as a chock for the tire being elevated with the BAL.
I take bottled water in gal. size, but a $25 water filter connected to a water source may be an option. If
dry camping, I'd still take the bottles of water.