There are 3 options, and the worst is definitely last...
1) join the union if possible. The training is more methodical. But as noted above, you might only learn to bend pipe. I know one like that. 10 years in the trade and didn't even know which direction to weap wires around device screws. Dang. Benefits are good. Work can be sparse at times. No unassisted thinking allowed.
2) get a job as a non-union helper. The training is more anecdotal. Learn a bit of this and a bit of that. You could still get stuck doing one job if you don't have some discernment. Pay and benefits might be lower, but you might also have more freedom.
3) the very worst thing is to get desperate and sign up for trade school with no experience. As one former boss put it - they'll teach you anything you want to know out of the book, then you'll go out and hurt yourself with a screwdriver

For real, I beg guys to never take this desperate route. I have never EVER met anyone who went to trade school first, then turned out to be a good electrician.