I'd say you're doing it right. Get a good idea of everything involved and weigh out the options.
Double check on the legality and practicality of where you plan to keep it. I had a bus years ago and failed to find anywhere to keep it. I lost it and am still bitter even today. Losing money and watching your dream vanish before your eyes sucks!
I wouldn't worry too much about lack of metal working experience. I worked in Steel and fabrication for all my life until my mid 30's and its all pretty easy stuff. Unless you're raising a roof, you should be fine.
Start looking into what makes and models suit your needs. I'm partial to Interationals
You looking to live in a bus or just build a weekend home away from home?