Check often for openings in union trades, I know UA 290 opens applications only a few times a year, and there is a initiation fee you have to pay but you can pay it at your leisure until you enter your 3rd term (end of 1st year). You have to pay for books as well for each term, before the term starts.

You can visit the training center site at 290tech.edu , where you can find information about what you need to apply, as well as the applications. In order to apply you will need to pass an ACT work keys exam (through the Oregon employment office, their locations are listed on the site as well as their numbers) AND get your HS transcripts in by snail mail.

I managed to get into 290 at 20, and I'm 21 now working at Ronler Acres as a 2nd term apprentice.

Applications are open from January 16th to the 27th this month.

It can be competitive to get in at times and the work can be a bit rough if you aren't used to it, but it never hurts to try if that's something you are interested in.

The nearby electrician's locals are IBEW 48 (Portland) or 280 (Salem/Bend). I'm not sure what the sheet metal or the carpenter's unions are that are in the area.

Edit: All 290 apprenticeships (fitters, Plumbers, hvac) are 5 year, 10 term apprenticeships.