I suppose it would be mostly practical skills, cooking, fixing things. Usually had to be done by people themselves.
Maybe also mental things like navigating (with or without paper map) and remembering their daily and weekly agendas.
What other things would be a big difference with the people today?
I never learned this. I always just browsed around and read what caught my attention. Maybe if I was doing research, I would have had to learn it.
It was a fairly regular part of our public school education