Just be honest and ask. You could get a grumpy response, but if you're going to work in a creative field, you'll have to deal with that a lot anyway. It's good practice no matter what happens. Hahah.
Photography
A place to politely discuss the tools, technique and culture of photography.
This is not a good place to simply share cool photos/videos or promote your own work and projects, but rather a place to discuss photography as an art and post things that would be of interest to other photographers.
Only way to find out is to make inquiries. Professional email is probably better than a cold call.
As a photographer, I’d be really worried about running afoul of labor laws if I had an unpaid intern. But I know how this business is, and there’s a lot of people that skirt the rules
I wouldn't recommend it. I did some unpaid "apprenticeship" work and it didn't teach as much as took advantage of free labor.
Workshops. Workshops are your best friends, dude.
It will be welcomed by some and bothersome to others. Just have to find the right fit. I did an unpaid internship that turned into a paid position.
Definitely look at workshop put on by working or recently retired professionals. Pay $150-300 for an all-day workshop, pick up some skills and--more importantly--meet the working photographers in your area who might be looking for interns.
Other workshops may be more expensive but you can likely find plenty for that price from professional organizations in your area. You usually don't have to be a working professional to join them or attend the workshops, either.
No way would I take someone on without paying them. I didn't have to do it, no one should have to do it.
I did that multiples times. Start with people you know, personally or vaguely, who are photographers or videographers. If that fails then Google photographers in your area. Google maps is handy for that. Mail around until a fish bites.
I haven't done weddings yet but I know wedding photographers always need a little extra help.
I did a few unpaid internships starting out in advertising and editorial portraiture photo. You really need to determine what you want to learn out of the experience. Weather it be the business side, lighting, onset direction, networking with other up and coming crew etc. many of my friends interned with top level photographers and didn’t get much face time with the photographer they were working for, mostly just helped with studio organizing, and ultimately just have a resume data point and not much else gained from the experience.
There are so many niche’s of photography, it’s hard to give the exact advise you need unless you clarify which area of interest you’d like to focus on.