How do I get a foot in the door as an apprentice with zero connections?

Started at 29 with zero contacts and nothing but a work truck I didn't own. The summer laborer gig is not a consolation prize, it's the actual answer. General laborers get hired constantly with no experience because the work is hauling lumber, cleanup, holding stuff, staying out of the way. Nobody expects skills in the first month. What they expect is that you show up five minutes early every single day, keep your phone in your pocket, and don't complain. That alone puts you ahead of half the new guys. Most small contractors are permanently short on help and the online listings get buried under applications, so yes, call them directly and better yet, walk in. A gc's office with a guy standing there in work boots asking for a shot beats twenty emailed resumes.

Did my time starting in the mid 80s and back then you'd just camp out at the lumberyard counter at 6am when the contractors picked up thier orders. Half of us got our first jobs that way, some kid with a hammer pouch and a good attitude. That trick still works by the way, supply houses know exactly who's shorthanded. One thing I'd add is don't sleep on the non-union residential side. A two-man framing crew can't afford to be picky, they just need a guy who'll carry plywood up a ladder all day. Six months of that and you'll have references coming out your ears, plus you'll know if carpentry is even for you before you commit to a four year program.

Gotta push back on the walk-in advice a bit. Walking onto an active site in work boots looking for a job is a good way to get walked off by the site supervisor before you say two words. General contractors especally, they have sign-in rules and safety orientation requirements and some office kid at the gate whose whole job is turning away random guys. The small residential contractor is a diferent story, sure. But if you're going to call or show up anywhere, do it at the office, not the site, and do it after you've got one week of laborer work on your resume. That first gig is what gets the door open, not the boots.

Agree with the guy who said small residential contractors are a different animal. I got my first six months of work through a labor temp hall, the kind that just places general hands for the day or the week. Showed up at 5:30am a few times, got sent to a remodel crew, and by the second week the contractor asked if I wanted to come on direct. No interview, no resume, he just needed someone who kept showing up. If the temp hall in your area does construction placements, that's a low-effort way to get in front of a dozen different contractors fast, and one of them will notice you.