Welcome aboard @Daco65, you have some exciting times ahead of you along with some right royal knee knocking experiences!
If you know for certain what van you are looking for then that is all well and good, but if you aren't at all certain then ask away as there are a lot of us on here who will be more than willing to give you some advice, mine being, unless you are good at welding, making certain you don't buy one which is known to have rust problems.
Welcome aboard lots of knowledgeable personal here!! That even sometimes give you good advice!! 😊 (couldn’t of done our build without them) remember there’s no such thing as a silly question. We all learn something from them, all the best with your research which is the most important part.