Windows 10 & 11
Under the Insert tab, click on either Header or Footer.
Pick the type/position of header or footer that you want to use.
After you select the header or footer, options will come up that let you edit text and add things like page numbers and dates.
To exit the header and footer tab, either press Close Header and Footer on the right, or double click anywhere in the document outside of the dotted lines. To quickly re-enter to edit your header or footer, double click around the text anywhere in the area above the dashed line.
Mac
Under the Insert tab, click on either Header or Footer.
Pick the type of header or footer that you want to use.
After you select the header or footer, options will come up that let you edit text and add things like page numbers and dates.
To exit the header and footer tab, either press Close Header and Footer on the right, or double click anywhere in the document outside of the dotted lines. To quickly re-enter to edit your header or footer, double click around the text anywhere in the area above the dashed line.