Contact your county extension office.
The master gardener program allows extension offices to increase their
reach using trained volunteers who barter a little volunteer time for
training and some cash for course materials.
You will have a blast, meet a lot of similarly minded people, learn 3x
as much as you expect, and gain access to all manner of hort resources.
It's not for everyone, but if it suits your temprement you can have a
great time.