Simple backend?

Question

CMS

Advise a backend for a website HTML(CSS,JS)
Which backend to choose so that it can be conveniently used by an ordinary user, so that even he does not have to learn
And the backend itself weighed little
For corporate sites, landings, etc.
Not for blogs and online stores, not needed wide functionality
Or is it that the user, if he wants to fix something, but he is a log, hires another person?
Does that mean I can't get carried away?
Sorry for the stupidity and thanks for the help =))