Daniel G, you remind me of myself. But regardless of how you feel it will be MORE than 3 years till you get out there. Her's my advice,
After high school you should think about going to college and getting a degree in forestry or agriculture. If not, get a job and use (some) of the money you save up to take wilderness survival classes, there are plenty around. ---> http://www.hollowtop.com/Schools_North_America.htm
This way you can get certified and later teach others as you save up money, a few years later the next step is to buy a plot of land. This way you are in the forest you love while keeping your skills polished and 'surviving' with others as well as getting paid for it. (this will take years....)
Land costs a lot of money and it is necessary to know what climate you want, how close to town, and where you want to buy your land. Surviving is not something you want to do full-time, because if your good at it, you'll have shelter and food in no time, and if your bad, it just won't be practical. Since your only 15 you'll be able to plan years ahead and be where you want to be sooner, but not if you rush into it and then screw up.
Parents..... If you are adamant about it, it should not matter if they don't approve. I'm only 19 but I've always wanted to do something like that and when I talked to my mother about it about 2 years ago she disillusioned me immediately, and basically said it would be very unlikely and I should focus on getting a high-paying job. (Completely ignoring my desire and not offering advice on how to accomplish it, just how it wold fail) My confidence was crushed and I did Research on the Military's SERE program, Park Rangers, Game Wardens, anything that alligned to my interests that I could make a career of, as my mother said what I wanted would be better as a hobby. None of them paned out after my researching. Then I discovered that there were survival school's everywhere with programs to train you to become an instructor if you take all their classes, and I decided to do that. The others options I mentioned might work for you and I would sincerely recommend you look up SERE.
--> https://enlistspecialforces.wordpres...f-sere-school/
But all in all I recommend you make your interests known to your parents and then plan on ahead anyway, if they see you are serious they should help you, as my mother has. Good Luck.

