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 think being good at estimations and having some intuition when something doesn’t match up for a restaurant bill or grocery shop is helpful though. And I don’t think a lot of people would get out their phone to double check the calculation.
But yeah, having this magic rectangle in our pockets is pretty nice.