Classes or groups to learn to build things?

I'm looking for classes or other ways to learn weld, use machinist tools, CNC, or other fabrication methods. Would really like welding, but interested in many things.

I've got a handle on fine art and woodworking, looking to branch out from there.

I tried looking for continuing education and night classes, but didn't come up with much.

Recommendations? Warnings? Secret Societies?