Gunsmithing, like most trades, is not something you can learn from videos and books, you must get your hands dirty. You will need varied machine shop skills as well as specialized woodworking skills ,business skills and the self discipline to put in an honest eight hour working day every day rather than BS ing with walk ins. Gunsmithing for many years entailed a seven year apprenticeship and upon graduation you were considered competent but not a master in all facets of the trade. Most gunsmiths in this country have little or no formal training in the trade, some are ex military armourers, machinists or advanced hobbiests and concentrate on one or several specialties, very few are equally competent on sporting rifles, milsurp, shotguns, handguns and custom projects. Specialists such as stock makers, checkerers, colour hardeners, engravers, and others provide their services to other gunsmihs that do not have equal skills.
Why do want to be famous as a gunsmith? Is it vanity? Do you equate fame with fortune? Can you name 6 currently active famous gunsmiths? The advice to first become qualified as a machinist, tool and die maker or perhaps a cabinetmaker is the best advice on here. You will never be unemployed and you will earn a very good living ( more than many university graduates) all your working life and even into retirement if you wish. With these qualifications you can always start gunsmithing on the side, perhaps specializing in one or two things to start then branching into more involved and skilled work as your knowledge increases and your customer base grows.
If you are impatient start by tracking down the reputedly best gunsmith(s) in your area and offer your part time services as a shop boy. All gunsmiths have lots of work that is dirty, repetitive and boring but requiring little skill. Many would appreciate someone to sweep the floor, make coffee, polish parts or take care of shipping. If you show promise and a good attitude you may in time be offered more challenging tasks and some training, but remember when the gunsmith is training or supervising you he is diverting his valuable time from his work to do it.