Beginner question about global page styles

How To
1

This is another silly beginner question.
Currently everything is working pretty well, but say, for example,
I want to add a global margin to top of each page so that there is a certain margin to the header.
How can I do this so that every new page looks automatically certain way.
Currently I am just adding margin to each first section which I think is not ideal.

2

Not sure if there is a specific setting for that in the Theme Styles but maybe you can try something like this in the Stylesheet section:

section:first-of-type {
    margin-inline-start: 6rem;
}