breeves, here is how my wife and I did it.
We started to think like you about retiring, selling the house, traveling mainly in the western US and Canada, and then settling again later. While we were starting to downsize and get the house ready. That was hard. To kill some of the pain we went to a dealer and looked at campers. We got lucky and found an exceptional deal on a camper that made sense for us. We returned the next day and bought it. Then bought a truck. The camper sat in our driveway for months and months with no use whatsoever except I tinkered and made minor modifications. When the house sold, we loaded the last of the junk in a storage locker and took off in the RV. We traveled for two years before returning to eventually settle near family.
If you rent a camper it is not likely to be what you want. A couple of weeks is not going to do much to help you make any decisions. It took us weeks, if not months, to settle in to full time RV living in a truck camper.
Instead of renting, I recommend you spend hours and hours looking at forums and blogs and you tube videos. To get you started I have some recommendations that fit might interests and will give you some things to think about and research further.
1. No slides, no popups. You want a camper that is fully functional if you pull to the side of the road to use the bathroom, fix a meal or take a nap. You want to be able to park and not look like you are camping. That way you can stay virtually anywhere.
2. No boats, no bikes, no towed vehicles, no motorcycles. Save all of that baggage for another time and place. Use your initial RV time for travel.
3. Be self contained. That means solar power, decent AGM batteries as big as you can fit in the camper, a generator.
4. Keep it small but with the comforts you need. I highly recommend a wet bath. A little water on the walls is nothing and you will keep the size down.
5. Be sure to get a unit with AC. You can't always outrun the heat. (AC is also one reason you need a generator.)
6. Consider a cassette toilet. You can empty it virtually anywhere and do not need to constantly be near RV parts and dump stations.
7. Work through all the logistic issues WELL in advance; including mailing services, electronic banking and income tax, cellphone with enough data to act as a hotspot for your laptop.
8. Look at all you electronic needs. Try to keep everything with 12 volts and avoid the need for 110 or an inverter.
9. I recommend you take a look at Northstar campers. They make a lot of units that are hardsided but fairly small and light weight. The designs are tried and true and the quality is well above average.
10. Research, research and then do more research. Learn everything you can about campers, trucks, RV maintenance, appliances, full time lifestyles, etc. You can get a wealth of information from the internet that will go to giving you a basis for making choices and decisions on what you want to do and what gear is suitable.