Credit card and cellphone...
I love these threads about, "What should I bring."
Sort of being facetious but some folks stop just short of a fully functioning machine shop on board.
@CatLightning you seem open to suggestions and you seem balanced and logical in your approach. I am sure you will figure it all out.
I d/l'd a few checklists that folks had in the library here and modified for my use.
The best advice I got here was to move into my RV for a week in the driveway. Only go into the house to get something necessary and to shower and evacuate (I chose not to fill up my tanks in the driveway - LOL) - Living in the driveway highlighted a few things I wasn't thinking about.
Going back to checklists I would recommend highly that you use an arrival/departure checklist that only contains these procedures. These are the things that absolutely have to be done before departing - jacks up, sewer/water/power stored, hook ups, "raiseable" antennas lowered, awnings in and secured, basement doors closed, departure route and surroundings are clear of collision hazards both ground level and trailer top level.
The last thing to do is a complete 360* walk around of the rig, a look underneath and a look up above.
I have a trailer addendum as well. I have almost launched with various things undone due to getting an interruption during hook up or something.