This was a career change for me; I somewhat infamously no longer build software[0]. I went back to school in my thirties to learn furniture making. I had never picked up a hand plane or chisel prior to taking classes. I started with some evening and weekend classes, followed by a couple of weeklong classes before applying to go to school full time.
As with learning any skill, I'd suggest finding a project to work towards to motivate you.
I was fortunate to have two full-time programs to apply to in the Boston area (now one, sadly). The biggest difficulty for finding training is likely going to be finding a place that offers it.
New England has the North Bennet Street School, the Center for Furniture Craftsmanship, Vermont Woodworking School, and maybe a few others. As I'm currently in Vermont, I know the New England scene the best.
[0] https://news.ycombinator.com/item?id=24541964