ChrisBach
Nothing's easy these days and having difficulty getting a foothold into plumbing is no exception. If you want to start a business (any business, not just plumbing) most people advise you to tell as many people as possible about it.
No different to your predicament of wondering how to get a foot in the doorway to a job or apprenticeship or whatever it is you're looking for, and it's hard work.
I'd suggest you write a list of 250 people you know. Don't know 250 people? I bet you do! While you won't always speak to them many you'll see frequently. You have some family. Presumably you have friends. Presumably you live with people rather than in a field or the jungle. You'll have postman, neighbours, supermarket checkout person you see regularly, garage mechanic/service manager, a builder you might know, etc, etc.
With these people, over a month or two tell them all you're thinking about being a plumber. Never chatted to the postman? Here's your opportunity and a chance to tell him what your plans are. One or two might say you're mad or a crackpot (and unfortunately it's worth listening to them!!) and many others will wish you luck. The reason you're doing this is that hopefully among these 250 people, a few might talk to one or two others (another 250 people) and between these 500 people or so, someone just might know of someone looking for a plumber or trainee or whatever it might be that you're looking for. Some might have great advice, others might be useless and ask you to mend their tap or change their hot water cylinder!
Unless you do something about it, nothing will happen. Money doesn't come to millionaires, they go to it. The same happens with a good step up in your career.
Good luck though with whatever happens.