Our interests in a class B are very similar to yours. We have had 2 B's. The first was a Sportsmobile Sprinter 2500 that we had for 10 years and 110,000 miles. This was pretty much a bare bones B but with a 12 V compressor fridge rather than the persnickety propane 3 ways. We chose to have 2 AGM house batteries installed so we would have enough electrical power for multiple days without being plugged in. As we totter into our dotage, it became clear that we would need more in the way of creature comforts so we bought a newer Sprinter from Advanced RV.
We generally go out for about a month at a time, south or southwest in the winter, up to the UP and then west in the summer. You and your spouse need to be pretty compatible for this to be practical. Even so, you will have to learn "the dance" of how to do things without interfering with each other.
Finding places to stay - There are lots of sources for this info but we have generally used the Good Sam travel book that has listings and evaluations of State and Federal campgrounds as well as the commercial RV parks. They provide telephone numbers and, frequently, instructions on how to get to the campgrounds. It's not perfect by any means but still useful.
Winterizing - Auto stores and stores like Walmart sell nontoxic RV and Marine antifreeze, aka the pink (or red) stuff. Empty all your tanks and pump this stuff through all your lines with some going to dilute residual water in your tanks. Think through how this is best done and then use common sense. If you are traveling in the winter, store containers of water inside the van but be sure to add extra antifreeze to the waste tanks.
Other sources - Search this forum for "The 12 V Side of Life." This will tell you all you need to know about battery power - very worthwhile. Visit www.sportsmobile.com. There is a lot of miscellaneous and useful information hidden in that site. They also have lists of used RV's for sale. If your B does not have a backup camera, get one. Garmin sells GPS units that are combined with a backup camera.
If you buy your B from a private owner, get him/her to tell you all you need to know about care and feeding. An RV dealer may give you some of the same info, but might not spend as much time or have the specific info as the owner. One hint - be sure to have some water in the black tank or solids may stick to the floor and be difficult and not much fun to remove.
FYI, I was born in the UP and still have relatives there. Does that mean that I am not a troll?
