Well, I did that all on my own, and before the days of computer and internet.
You can learn in a day, what took me a month, Just make notes of everything, they are great reference because you certainly won't remember it all. One advantage, my dad was a millwright, welder, structure engineer.
At 16, I built my first dragster around an old Chrysler 500 hemi engine.
Does your school not have metal or auto shop? Mine did.
An early entry job was making gun barrels for M-60 machine guns and M-16 rifles. worked up to making parts for fighter jets then changed to RF engineer, saved money to get my MSEE. retired now.
Work and save money, when ready, start with trade schools. a parallel is a hitch in the military then VA can help.