Congrats and good camping!
I found I could greatly increase my confidence and save time and money by familiarizing myself with the electrical system. We never plug in to 120 volts when camping. I tried to keep track of battery charge with voltmeter (overly optimistic until several hours after charging has stopped) and hydrometer (too awkward to measure in place and too long to take the batteries out), finally finding satisfaction with a $25
Battery monitor Be advised that damage to regular lead-acid batteries occurs when discharged below 50% capacity (12.0 volts with no load).
Caulking is important! It took a spoiled trip - water dripping on the bed in the middle of the night - to teach me that! Even tiny cracks in caulking or slight loss of attachment can cause trouble. Now I check all the roof caulking before every trip and repair or replace anything suspicious.
Tire pressures are important. Lots of good threads here. Be sure you have the tools to measure and top up the pressure in the dual wheels. I gave up the wheel covers to avoid buying special valve stems and manage well with a regular straight/backward ended gauge and inflation tip for the best Walmart air pump.