My apologies about being so brief. I have a serious cold and wasn't feeling good.
Let me expand:
Fridge. The most usual reasons these fridges don't work well is air flow. They need a good vent front bottom to top. If your fridge is in a side, then that's even more of a problem because the top vent is just barely about the fridge coils. Regardless, take the top vent off and look down into the slot that exists on the back of the fridge. This is all outside. You should see a clean pathway to the bottom. Any excess empty areas need to be sealed. The only obstructions you should see are the fridge coils.
My fridge cools better on AC than gas. I took apart the bottom of the burner assembly( 1 screw) and found mud dobber houses. Cleaned those out and bought screens for all my burner ports( fridge, water heater, heater). Cheap. I used silver tape to seal around my fridge vent area to make for smoother air flow. There are you tube videos showing these issues and fixes.
Solar. I recommend you live with your current system until you know your current draw. I changed all my interior lights to leds. 16 bulbs. Then both my wife Ava I got used to changing our lifestyle to limit battery usage. I went from 1 12 volt battery to 2 6 volt golf cart batteries. That was a huge improvement as they can be drawn down before 50% without damage. But still not enough. We boondock fire a week at a time. I bought a 100 watt solid suitcase(Renogy) and it works great. But we wanted more. Finally made the leap to lithium. 200amp battery. Moved it inside near the power center. Kept the old battery wires up front to be used as a emergency power tap or to connect up the solar. Rewired the input/output of the power center to the new battery. Added a battery shut off and a shunt. I can now go camping for a full week without charging! We don't use the microwave, or hair dryers so no need for an inverter. I spent 2 years living with trailer, learning from you tubes and forums. It's really simple stuff. BTW, I'm 76 years young. Retired. Not an electrician!!! I did it, you can too.
Tires. Goodyear Endurance. Pay the money upfront. Keep your tires inflated to close to max cold rated on tires. 65psi is max for "D" rated tires. I run 60 psi since my rig, loaded, is less than the trailer max. My trailer max is 6400lbs. It usually tests at a CAT scale from 5600 to 5800lbs. So i run 60psi. Perfect for my rig.
Load up. Full water, full propane, empty waste tanks then find a CAT scale. Weigh your truck, your trailer then both. You tube videos on how to do that. Most scale guys will work with you and help you out. Just remember, truckers come first.
That's it for me. Welcome to the RVing club! Be safe, take your time and enjoy learning this new adventure !