Welcome to the CRVL Forums
You've found a very good place to learn and learn and learn. I haven't been posting here much of late as I've been working on my own rig after a 100 degree + summer and just getting some weather where I can get some things done. But I'll share some thoughts. If you go with a Van try to get something that would be dependable. That would have a few years of usefulness left in it. To start out with you would be taking week end camping trips and after awhile some road trips on the three & four day week ends. These will be your first steps just to "shake down" (meaning to learn) and get your legs under you.
Of the vehicles the high top Vans have been quite popular as you can stand up in them. In a regular Van you will be bent over at the waist a lot and it gets old. You may find a Step Van (like a bread truck) but you'll need to give thought to where you will park it when not being used. That can be an issue if you are still in the sticks & bricks. As for equipping the vehicle, a suitable bed, a cabinet that would have a top for a basin to wash dishes and prep food, a cooking top like a two burner propane stove, and space below for kitchen stuff, canned foods, etc. An ice chest of at least 42 quart with 20 lbs of ice could carry you a through a weekend. If you can spend summer weekends doing this your first year you'll be ready to experiment with camping/travel by the next year.
To get yourself equipped, shop Flea Markets, Yard Sales, Goodwill stores, etc for kitchen equipment, bedding, camping equipment, etc. Dollar stores will often have a lot of things that are quite usable.(such as food containers for storage) Visit websites like CampMor com and look thru what is there and then try to find stuff like it in yard sales & flea markets etc. And remember to try and find stuff that can be used for several things. In this way you can be more of a "minimalist" and not look like you are toting every thing you own along with you. (like you're going homesteading)
This is much of the essence of it all. Carry a laptop with you or a good cell or tablet so you can...if you need.....get the weather forecast, find locations of goods & services you would need while on the road. (such as laundromats, vehicle service, medical facilities, etc)
Below are a couple of my websites which I put together to help others who are curious about this life.
In the first site at the top (Van Conversion) there is a link at the top "My Own Story" about how I got started into this. We all come to this with different motives.....mine was to get started in my career right out of school days. Others may just want to travel in their retirement etc) Below in the next link "edjautoservices" is a portal of handy information as a portal site. It is designed to help people stay safe, be comfortable, and enjoy conveniences while away from home or if living full time in a rig.
Good Luck :thumbsup: