Assuming the rig is new, the antenna is probably a King Jack. If you recall the shape, you can identify it on a web search picture.
If you don't plan to boondocks then one battery is sufficient.
Regarding PDI items (assume you are referring to the roof) I would check the following;
-all sealant is in good condition (this applies to the rest of the trailer as well). Once you leave the parking lot, any warranty issues resulting from insufficient sealing will be yours. I think the sealing requirements are to be verified every 90 days.
-ensure solar controller is functional. (ie, either via controller display or voltage measurement)
-ensure digital antenna rotates to stop points (inside) and that the green light is on the amplifier output that feeds the TV.
2016 RAM 3500 6.7L DRW
2018 Chaparral 360IBL, Andersen Ultimate II hitch