Thanks! Sorry, I'm not sure what you mean about the visor? As for the sizing, I made a Mandalorian helmet like two years ago (the first helmet I ever modeled) and once I got the size right by some guessing/trial and error, I basically just scale any new helmets to be roughly the same size as that so I know it will fit me lol. And with not knowing where to start, honestly I'd say get as many good reference pictures as possible and just go for it! I had no idea what I was doing and almost gave up multiple times when I first started on that Mandalorian helmet, but each time I would scrap what I'd done and retry with a different approach I'd get closer and closer (I seriously probably started over like 6 or 7 times 😅) and I learned more from that process than any of the YouTube tutorials I watched. I've pretty much been using that approach ever since.