I had to talk Ds through this, he finished uni and started a graduate job and needed to build his credit score. We had transferred his phone contract to him earlier even though we still paid it, just to him and he had the direct debit set up.
I had to talk him through the whole 56 days credit or whatever it is, I just know when my own credit card rolls onto the next month and when it is due for payment. Mine is paid off every month in full and has done for 25 years. It is a Tesco one so clubcard points have paid for hotels in the US, days out here ie Legoland, RAC cover, magazine subscriptions, Disney Plus. So they were always aware of the points but not the minutiae of how it worked.
He applied for a credit card and just buys his lunches on it, train tickets etc but it is set to pay in full automatically every month. However, we as a family have watched stuff on people in debt, spending habits and how long it takes to pay something off, wants vs needs. But then I have done debt collection as part of my job with income and expenditure forms so they know about that too.
I think it should be covered in school because not all people understand it. My children were told about some things but it was more what salaries can be earned with these jobs and what house can you afford? Most will be living at home with at least a minimum wage and so spending should be talked about.