Greetings & Welcome!
A job and income first and foremost. If you’re planning on traveling, then a mobile friendly income.
Vehicles are relatively easy. First decide if the ability to stand up inside is necessary.
Passenger vans, shuttle vans, and buses are all available, and make good camper vans, cargo vans not so much. Starting with something that has already finished floor, walls, and ceiling will save you a ton of work and expense.
Window vans are the stealthiest, and easiest to park in towns. Even high top ones. For a single traveler, I think vans make the best sense. For two or more, bigger is better.
Older vans can be found pretty cheap, and the pre computerized ones are known for their longevity, durability, and reliability. Mine is a 1973 Dodge Maxi-Wagon(van) with a high top. It is approaching 500k miles on the original engine and transmission, and still going strong. I purchased it over 10 years ago for under $1,000 and it has been very reliable and never had a major breakdown. Just normal maintenance, and still runs and drives like new. Just drove clear across the country with zero problems.
The next thing to consider is what amenities you want. Even though I built my own, I have everything a legitimate motor home would have, a toilet & shower, kitchen, heating, cooling, and power. Since I don’t normally stay in campgrounds, I have to generate my own power through either driving or with my generator. I gave up on solar panels because they weren’t reliable enough for me. They were a huge added cost with more negatives than positives.
If you’re not planning on doing much on street parking, older motorhomes are also worth considering. They can be cheap, and are move in ready.
"I can live like a king because I work like a dog." ~ An anonymous vandweller