Hi Marty. I haven't had a great experience attempting to paint - hopefully things will turn out better for you. I bought rolls of clear builder's plastic and lengths of conduit and constructed removable walls that hung from the roof of the shed. I put an extractor fan down on the ground at a door with the rest of the door blocked off so the air was drawn over the tops of the plastic walls and down to the floor level at the fan. That aspect seemed to work well. (I can add photos if you'd like, but at the moment I'm on a PC which doesn't play nicely with the format that the iPhone produces. Yes, I know how to deal with it, but I'm being lazy...).
I painted the cabin interior, but decided that the results, though ok, weren't really good enough for the outside. Maybe I just got frightened and it would have been alright? I don't know. I did show some examples of my work to my paint supplier (an ex-spray painter) and his response was "Not bad, but doing the outside would be a bridge too far", so I gave up and have sent it to a commercial shop recommended by some other blokes in my SAAA group. Sadly, it's been there for a couple of months, and it's still not finished. There's always some "big commercial job" that he's had to do and it's always mine that gets bumped. 😞 Whinge over.
If I was trying again, I think I'd leave the interior until I'd built up some skills. Trying to work inside the box that is the baggage area was difficult as I kept bumping the gun against other recently painted surfaces. I'd suggest doing lots of practice sweeps without pulling the trigger until you're confident that you'll get the coverage without the contact.
Oh, and I had a couple of worksite lights hung at different angles, but like iBob said, too much light is never enough.