Hi Michael, and welcome.
As Colin says, there's a TREMENDOUS range of different vans out there, so you need to do some whittling down.
A few really important questions.
How many of you are there? (watch out for vans which have lots of berths, but not enough travel seats)
What sort of use do you plan to make of your van? If you'll mostly be staying on full-facility campsites, your requirements will be a bit different from if you intend to wild-camp, or use "aires" on the Continent.
Are you happy to make up the bed every night, in order to get more into a smaller vehicle, or would you put up wiith a bigger van to avoid that chore?
There are lots more, which is why Colin rightly advises you to do a lot of looking around dealers (and maybe shows), and possibly hire before you buy.
But once you're up and running, it's a TERRIFIC lifestyle. Enjoy!