I have seen some video courses, and I have seen correspondence courses advertised. Neither gives the kind of hands on experience you need to get started without learning on someone else's guns. Still, both are valuable, and a good place to start.
It would be tough where you live, but you might ask at gun shops if they have any need for a gofer/trainee who could work with their gunsmith, but unfortunately they have more of those kinds of guys showing up than they can possibly use. There is one smith in the area whose work I have seen and I can only say you could not possibly do worse.
To go into business yourself, you need both age and capital. I don't think you can even get a gunsmith's license until you are 18 or 21, I forget which. And you would need a business premises, which would be at least difficult in Mont. Co., not to mention expensive.
Wait a while until you are more on your own, get some college education under your hat, and bide your time. I don't know what you are planning to study, but if you think of going into business on your own, business courses will help even if they don't lead directly to your major.
(If KKT is elected, we may not need any gunsmiths in MD; the guns will be in the furnaces and the gun owners in re-education camps or maybe death camps.)
Jim