I recommend reading the "Little House in The Prairie" collection wherein there was a one room school house and a twelfth grade grad taught it. If she made it thru high school, she knew enough to pass along her education.
My mother went to "Normal School" A Normal School was a two year, post high school program. Year one was spent in a classroom learning how to teach. Second year was spent in a classroom observing and being observed by an experienced teacher. She went on to college and law school but ultimately chose teaching. She pretty quickly advanced to principal.
I greatly admire those who home school. I could not begin to do that despite having a fist full of degrees.