I have given up on trying to add items to my previous list because my HTML skills are rudimentary and the numbered items are set up as a table and won't let me add new items.
Anyway, here are a few more serious things I have learned over the years and thought some of you newer folks should know about. I will put them in paragraph format so I can more easily add more items.
First, I was reminded today that if you take prescription medications, the bottles will tell you that they to be stored at a certain temperature range--roughly room temperature. However, RVs are like cars in that when parked, they tend to get very hot or very cold unless you are plugged in and using your AC or heaters. I was told by a couple of pharmacists that the best way to store medications is in a small cooler, but without ice. The cooler will help the temperature stay more consistent, and more like what would be room temperature in a house.
Second, RVs are a lot taller than cars and thus are more sensitive to side winds or the wind caused by big trucks as they pass you. Most of us who have been on the road a few years know to either get off the highway if winds hit 20-25 MPH, or at least slow down substantially, like to maybe 45-50 MPH, if you cannot get off the highway safely. For this reason, it is always a good idea to add an extra "emergency" day to your travel plans.
Third, related to the above, know how tall your motorhome or trailer is. If you want to see what NOT knowing the height or your vehicle is, check out this website: https://11foot8.com/ (The bridge has been raised a few inches, but the results are the same for drivers who do not know how tall their rigs are.) The best solution is to get a GPS system meant for RVs or trucks where you enter your height, plus a few inches just in case, and the GPS will keep you away from low bridges and the experience of losing a vent cover, AC unit, or your entire roof.
Fourth, speaking of dangers, your front tires are critical, so make sure your newest and best tires are on the front. I have had three blowouts of rear dually tires, and it was really scary. Never try to drive with one dually blown, as the remaining tire cannot handle the extra weight and will also blow soon, causing a lot of damage to things underneath your vehicle, as well as possible body damage. Pull over immediately, stick out some warning cones, and call road service. It may take a couple of hours for someone to come and change your tire, but you at least have a bathroom and refrigerator with you, which cars do not!! So, sit back and relax, and hopefully you have a good road service company such as CoachNet.
Fifth, and an addendum to the item above, make sure you always have a good spare tire. You cannot count on a tow truck to bring a tire you can use temporarily. Plus, they cannot tow you with a blown tire, so you are going to be stuck for a long time on the side of the road waiting to get a new tire brought to you. (And do I need to mention that you should always know your tire size and carry some orange cones or triangles to put out on the road??)
Sixth, If your vehicle does not display tire pressure and temperature, you might want to buy a tire pressure monitor that sits on your dash and add sensor caps to each tire. I got tired of constantly worrying if my tires were inflated correctly or were ready to blow, so I got a TST 507, but there are other brands. It is a little tricky to program each tire cap, but well worth it to know that your tires are OK and not underinflated or overheating when you are going up or down mountains. Also, I can turn it on before I drive and watch it as it cycles constantly through each tire. No more worrying if a strange noise means something wrong or is just due to a weird road.
Seventh, know what your rig weighs and what its maximum cargo carrying capacity is. The cargo carrying capacity, or CCC, is on a yellow sticker somewhere inside your motorhome or trailer. CCC is how much stuff you can carry on your RV above what it weighed when it left the factory. This includes the weight of water and waste in your tanks, passengers and driver, pets, clothing and personal items, bedding and towels, groceries, various equipment such as tools and outdoor toys, and anything else you bring with you. Being overloaded can cause tires to blow, a rough ride as springs and shocks are stressed, and even frame damage, so you need to periodically weigh your rig as you travel.
Eighth, you can never have enough flashlights. Walmart has some really good, small flashlights for $1.25, and I carry several extras, but you also need a couple of bigger flashlights. I have small hooks on exits so I can grab one in case of an emergency in the dark.
Ninth, mice and other critters like that we provide them with nice, warm homes while we are camping. I don't know how they get in, but I suspect they crawl in through small holes underneath our rigs or cracks in slides. In any case, they DO get in, whether your rig is in storage or you are camping. A year or so ago while camping in the desert in western Colorado, I was watching TV at 11 pm with all the lights on in my motorhome and sitting in my recliner. A little fellow came out from under my sofa, and looked up at me with surprise that a human was actually there. At midnight, I was outside with a flashlight trying to find my mousetraps with no success. The next day I had to drive 35 miles to stock up on traps, but that night I caught two and then caught three the following night. Left the next day for a place with fewer mice, but I strongly advise you to stock up on mousetraps, traps and powdered borax for ants, and a variety of insecticides before you take a long trip.
Tenth, pack rats are common in the desert and very interesting animals because they dig burrows and protect their burrows with cactus nodules. They also like to steal colorful objects from campsites and use them to decorate their burrows. However, they have a very bad habit of getting up under the hood of your motorhome or pickup truck and chewing the wires. Those strings of lights people buy are very handy to put UNDER your rig, not hanging on your patio, to discourage pack rats. If you do not have lights or an electric hookup to power any, the best thing is to open your vehicle hood and leave it up all night.
TBD - And feel free to suggest more tips for newcomers in a comment!!