Advice on part time use....do's and dont's

Tomorrow I will have my new TT set up at a campground on a lake in Al. It has full hookup (elect., sewer, water, etc). I will leave it there for at least 6 months and come and go. What do I need to do (must do's) when I leave for days/weeks? I plan to leave AC thermostat on 75 and fridge on of course. What else ?
Many thanks!