I came from a working class family in the Chicago area. We were not necessarily expected to use “sir” or “ma’am” when addressing our parents, but we were expected to show them due respect. My wife was raised in a military family from the Southern US. She and her siblings were taught and expected to use “sir” and “ma’am”.
Growing up in the North, we called most adults Mr. or Mrs. (last name). Adults who were friends of the family were more often called “Uncle” or “Aunt” (first name), even if they were more accurately cousins or friends. I noticed that in the South (generally speaking) I children would address adults as Mr or Ms. (first name).
As far as school, I always addressed my teachers as Mr. Miss or Mrs. and then the last name. This was before the widespread use of Ms. Of course, in Catholic schools, the priests were addressed as Father (usually last name), or Sister if the teacher was a nun.
As far as using the teacher’s first name:
I had always thought it was more appropriate to keep the Mr. or Ms. followed by the first or last name, depending on the teacher’s preference. I see a certain level of respect which is inherent in that practice.
That being said, my daughter attends an expeditionary learning school, and I teach music there part-time. It is part of the culture of this particular school that the students address the staff on a first-name basis. The explanation is that the classroom in this particular type of school is modeled after the typical 21st-century American workplace.