Newbie help request

I’ve read the FAQ, browsed the home page and most of the links it goes to, etc.

Now its time to get started. I’m looking for any help I can get to a) Buy a
cycle somewhere in the Greater Boston, Worcester or Southern New Hampshire area.
b) learn to ride the thing. So, any used but not too abused 20 or 24 inch
machines up for recyle in this area ? any newbie tolerant clubs or groups I
could get in touch with ?