That’s cool - I’m excited for you. For many gunsmith tasks there are similar skills in automotive. The preferred Ceracote sprayer is just an automotive detail gun. Metal polishing and finishing overlaps across a number of industries. More than one automotive machine shop has threaded a barrel after hours.
I’m from a different trade and not qualified to give advice, but rather a fly on the wall enjoying any and all gunsmithing chats - cheering you on. I’m the small town curious kid that has shown up just to say hi and see what’s new at the local gunsmith’s shop enough to have been an annoyance in every town I’ve ever lived in.
25 years in a trade with about half employees and half self employed, not to mention seeing the same in numerous other trades, you’ll soon find that making the transition is usually done gradually. Keep a steady income until you have the business end figured out and are so well established with work in the pipeline that it’s a no-brainer to switch completely, and maybe you never switch completely.
I tell everyone in my trade the advice given to me 3 decades ago by a retired and very successful mentor. If you start into a new trade, or same trade in a new town, go to work for the best guy in the area, even if it’s part time and miles away. You will quickly learn the faces, names, practices, suppliers, business aspects, etc. that work well together - all stuff you can’t read off a website or watch in a video.
Pick up a $50 take off barrel and cut/thread the muzzle a dozen times clocking the brake, then cut off the other end and rethread, clocking to match your rifle. If you’re like me that will cost $50 for the barrel, $1,000 in tooling/measuring, and a couple hundred hours of head scratching, but you will learn a lot. None of it will be right, however, you will now know a little more about what you don’t know.
If you have to teach yourself safety around the lathe, google some accident pictures and it will imprint how important it is to not get wrapped up.
Best of luck!