I've been camping in trailers for longer that I care to tell and have seen all the mistakes and made a bunch of my own. Here are a few tips:
The stabilizer jacks are not there to level the trailer. Have a level handy when you arrive. You level the trailer side-to-side first, by raising the "low" wheels. There are several different setups sold for this. For front-to-back, you use the front jack. After the camper is level both ways, THEN you lower the stabilizer jacks. If you use the stabilizing jacks to level the trailer, you could either bend the jacks (needing replacement) or bend the trailer's frame. The off roads frames tend to be sturdy, so the jacks will probably take the damage.
The surge protector is like a gun - Better to have and not need than to need and not have. A couple years ago I was camping in Virginia and lightning hit a power box. The only trailers not damaged were (like mine) hooked up with surge protectors. Don't go cheap on that. buy the best you can afford.
Practicing the back-up is the best idea. My wife is my guide when backing into a site and we use walkie-talkies to communicate. It saves us the embarrassment of the neighbors hearing all the swearing that naturally happens while doing the maneuver.
If you hook up to camp water, have a pressure regulator and water filter in your kit together with the hose. You never know what will come out of that pipe, and how strong.
If you can afford it, put Lithium batteries in the camper's box. I bit the bullet a couple years ago and put in a 50Amp/hr one to replace the old battery. It weights only 5 lbs has more than twice the output of the old battery, which weighted 20. The day of the VA storm, it kept my refrigerator and lights going for several hours while we waited for the electricity to be fixed in the camp.
The setup/strike camp list and the safery check "4896 worker" advised are true and wise. Do them.
Enjoy your camper in the best of health, safety and good company!