First Long Trip - How to Prepare?

Do you have a spare tire, if so check you tire pressure.

Dont forget about your tow vehicle.

I try & use my RV before a long distance trip. Sort of a shake down to ensure everything is ok & no major issues.

If you have any work done by a shop i.e wheel bearings, brakes etc. have it done far enough in advance so you can use it & get any problems they missed fixed or the ones they did corrected.

I've always subscribed to the idea that my trailer is always ready for travel. If something needs doing it happens right after we return to be sure it's ready. Nice to be able to leave the next day when an opportunity presents itself.

Factory tires may be a problem but not always. Mine came with Maxis installed because that was negotiated in the deal. Can't do better than that.

Good luck and hope you have a great trip /skip

You said you have a pressure/temp tire system but I would really keep an eye on those year old china bombs. I carry an IR temp gun in the truck door pocket. They are getting very cheap to buy and will spot trouble early. Just look for large differences in tire temp and don't worry so much about actual temps.

At a year old you need to grease the wheel bearings too. Be sure you actually check your tire wrench to make sure it fits. Many people assume (wrongly) the truck wrench will fit. A bottle jack is the way to go.

No need to carry something to lay on unless you have plenty of room, you can use the truck's floor mats in an emergency. They provide good cushion on gravel too.

A walk-around should be done every time you stop or get out. The exercise will do you good and wake you up.

Going to Big Bend is an experiance.
Check your interior of your rig for any supplies you may need. There isn't any places to run and get what you forgot.
Look through the galley for pots, pans, utensils and dishes.
look through your groceries in the rig. Make up a "menu" for each day to see what you need to stock up on.
When you get close to Big Bend, check your propane tank(s) and TV fuel.
If you are dry camping, make sure you have fresh water. Grey and black tanks empty?
Others have covered rig preparations.

Also, my dad taught us to check the wheel hubs immediately after stopping for excess heat. The reason for doing it right away is so the heat from the brakes doesn't have a chance to radiate into the wheel hubs. Otherwise you will get a 'bad' reading.
You will be able to tell if one of your bearings is having issues because it will be hotter than the rest.

A long trip is just a series of short trips unless you plan to drive it in one day.

X2. Get going. Carry a credit card.

On any trip long or short you may want to do the same thing the commercial driver do. Have a pre-trip visual inspection. Tires, all exterior lighting, hitches and safety chains etc. Then at every rest stop or fuel station you use do the same walk around your RV. If you have a MH with duals carry a thumper with you. If you practice these procedures you won't eliminate all problems but you will limit many problems that go un-noticed. When I am at rest stops or in fuel stations I see very few Rvers making walk around inspections. I just always wonder why. However, I was trained as a commercial driver so that is just what I do.

All good tips. I appreciate the info as there are many things I didn't think of. I typically have all the tools I need as I have a decent sized tool box in my garage but I know I don't have a bottle jack. I'll be purchasing one this week.

Good advice here, all.
My personal experience and that of my friends with whom I travel is that when the cheap tires fail, they do so catastrophically,as in belts separating, coming off, etc. If you are going on a cross-country run, not just down the road a bit, it might be time to upgrade your rubber. Not cheap but it will save you money if you have a catastrophic tire failure and the tire peels your rig open as it disintegrates.
Other than that...
I check the RV from stem to stern, as best I can. Torque the lug nuts, check the lights. As stated, if you are really making a long run jack the wheels up and check the wheel bearings for slop, grease and adjust as necessary.
Check and if necessary clean the battery terminals and all grounds I can see/find. Battery water if applicable. Check and change (if necessary) the oil in the generator.(My new Onan requires it's first oil change at 10 hours)check the seals and trim, fix and tighten as needed.
I am one of those guys that tends to carry spares...fuses, an extra fresh water pump, bulbs, tools, etc. I have box that rides in the pass-through compartment with all that stuff. I make sure everything is good in it. I go into overkill, admittedly. I've been RVing a long time and have had the Fickle Finger of Fate point at me a couple of times, so I do everything I can to prevent it and be ready for it if it does. We spend a lot of time traversing or camping in areas where people and towns are few and far between, so being ready is my motto.
These RV's are subject to all the beating and banging that our cars and trucks are, but they are not built like cars and trucks. Eventually stuff comes loose and if you don't maintain it stuff falls apart.
I carried a big floor jack for years, now I have a 20 ton bottle jack. It takes up less space in the 5'er. I am a hot rod guy, and I have a Craftsman 19.2 volt 1/2 inch impact gun, it is great for lug nuts...years ago I bought a second Mac torque wrench for the RV, and it is in the 5'er now.