Help Planning for Specific Build

Hey everybody!
Im just starting out, for the moment Im living on the road out of my 2013 Toyota Avalon, as cheap as I can and relying on many public amenities. I feel bolstered more than ever to choose this life, but I have a specific vision, and would massively appreciate any expert/long time vanlifer’s opinions and assistance in planning for it.

I don’t feel this is too crazy to shoot for a dream setup for my first vehicle, especially with what little knowledge I have, but I feel I am the kind of person to pursue rigorous research, planning, and risk calculation for my future. I personally think giving myself the time now to think this through can really make it happen, but I need help!

TL;DR i have big dreams and no prior knowledge here.

I need help planning the right vehicle to modify legally in order to make a mobile “stage”, while also accomodating typical accessories and amenities like a 1-2 person bed built in, compartmentalized spaces, weather-proofing for camping outside, etc. I understand theres much to be done and a lot to unpack, and I have some resources such as family metal workers and mechanics to help me outfit the vehicle.

Which vehicle??? I am not a motor specialist by any means and have very little knowledge and opinions of automobiles or manufacturers.

Which vehicle should I start considering to be able to
A. Live out of full-time on the road
B. Accomodate camping (not opposed to roof tenting/hammock attachments etc)
C. install a side panel (like a food truck maybe?) Or some other way, like an outdoor popup w/generator power to accomodate a compact live music station.
D. Ideally, due to my lack of mechanic thumbs, be common enough for parts replacements/accessible repair.

I cant wait to see your beautiful brains work, any and all advice is appreciated!