[Toolman]

I guess a lot depends on what you want to do as a 'smith'. Some people are content to just install scopes and change out broken parts.

If your goal is to build custom guns and do more than just install scopes & parts then you should invest your time learning to be a machinist. To do it right you have to learn precison benchwork as well as precision machine work.
As Ed said, learning to use a file properly (lift after each stroke & keep it clean) is a small part of the trade.
I'm 59 years old and have thought about gunsmithing as my second career.
I finished my diemakers apprenticeship in 1974. It wasn't in a union shop, so all I could get at that time was a state certificate. I have worked as a machinest & diemaker my whole life and it has been my preferred life's work.

Last April my gunsmith mentor & friend died after 65 years in the business. He was a high school machine shop teacher. His workbook is still published. He taught my father, who in turn taught me. He taught me a lot, but I didn't get to spend the time with him I would've liked to. It was really,really, hard for me to go into the machine shop area of his gunshop after he died.