First slug of RV supplies for a first timer. What do I need?

^Spare wheel bearing and seal for the trailer axle.....the list could go on and on.
On big trips I pack more tools and parts than one probably should, lol.
Bottle jack is handy sometimes too.
But keeping it to just “camping” related items. To the OP, start small and build up as you need things, or your first trip will be carting the whole house and shop in your RV!