My kids (twins) were slung into car seats and started "riding" not long after I had them. Our first long trip was a 14 hr trip to Fl. I well remember sitting in stuck in traffic on the "285 parking lot" (Atlanta) hanging over the front seat bottle feeding both girls at the same time. And then I changed diapers on my lap. I had a dog squeezed in between the girls' car seats. It gave the trucker next to us a good laugh. The girls were 2 months old. Haven't stopped going since. We would load the kids and the dog up on Saturday morning and daytrip someplace. Usually not get back until late at night... sometimes the next day. David & I always went and after I had the girls, they went too.
I kept a "go bag" of clothes for my husband and myself and an extra diaper bag with two complete changing of clothes for each of the girls, food, formula, and LOTS of diapers in the car. We started them out in a onesie under a soft sweatsuit (mornings were always cool), and then we would layer up or de-layer depending on temps. They slept a lot at first. I also carried a pack & go playpen which would double as a place to sleep when we stopped.
I also put a walking harness on my kids and a leash. This allowed us to take them hiking and not worry about them falling off a cliff or heading into the creeks. They were 6mo when we first took them up to Angel Falls (Rabun Beach Recreation Area, Clayton, GA) which was in one of our favourite campgrounds. We would picnic in the campground and then hike up to the falls. My kids have a deep respect for nature. If you do the leash thing, be prepared for strangers (and family) to make nasty comments about it. My mother disliked the leash thing. After she lost them in a department store, she changed her mine. This was long after the Walsh kid went missing (they found his head a few miles from where I lived in FL at the time) and many stores had already started "ADAM" procedures. The store was locked down within minutes. She was embarrassed about that for many years. But she became a proponent of leashing kids in stores and parks. I loved my dog and I leashed her for her protection. Why would I protect my kids any less? A leash gave my kids the freedom to walk around and not be carried all the time. I think it helped them to become very independent at a young age. My kids are now adults (one is a mother). They still think that leashing is a good idea.
When they got up to "finger-food" age, I would put a hand full of dried cheese filled tortellini (my local Winn Dixie carried the DaVinci brand) in a pint jar and fill the jar with boiling hot water and screw a cap on it. By the time they were hungry, the tortellini had absorbed the water and the cheese filling was rehydrated. My kids loved the stuff. This was either their lunch (with additional food added) or it was their snack. They stuck the round rings on their fingertips to eat them. amazon.com/DaVinci-Multicolor-Tortellini-7-Ounce-Boxes/dp/B000FD9314/
Another thing. I know that everyone thinks that RVers are practically perfect and they never steal or any other bad thing. But the fact is this, you will be around people that you do not know in campgrounds. ANYONE can and will buy an RV. That includes people who steal and/or abuse kids. Don't turn your back on your kids for a second. Don't run inside your RV "for just a second". Someone can take your kid and be gone very quickly. It did happen in a public campground that we were in. Luckily the park rangers closed the gates before anyone left. We all got searched. They did find the kid safe. The kid HAD been taken by some "nice people". We never found out why. But we did hear from the park rangers later that it wasn't the first time those people took a kid. And every one had commented on how nice and friendly they were.