1. Four way tire wrench to change flat tire on camper
2. 2 ton hydraulic jack (for changing flat tires)
3. Ratchet and a socket to fit anode rod on water heater
4. Leveling pads
5. Plan to get a decent mattress and discard the crappy factory one(s).
6. Black/grey water treatment
7. RV toilet tissue
8. Sodium Diclor to sanitize fresh water tank, no chlorine stink and only a teaspoon to 100 gallons of water. Cheap & A small bottle lasts several seasons.
9. RV Surge Guard protector.
Surge Guards, Surge Protectors, Voltage Converter, 30-50 Amp Surge Guards - Camping World
10. Spare fuses, elect tape, duct tape, light bulbs, misc tools.
and any 'creature comforts' of your preference.