Place the cursor where the new section heading needs to be created.
Do not type the digits of the section number or manually change it into a heading with the paragraph and font settings under the Home menu tab.
Instead, select the text, and apply a Heading style of the right level for consistent formatting and a uniform layout with a single click.
There are 5 pre-made levels, and heading levels can be changed with a single click.
To then insert a clickable link to a section (i.e., a cross reference) somewhere else in the text, place the cursor where the clickable link needs to be inserted, go to the References menu tab, select Cross-reference, look under Reference type for the heading, and then insert the cross reference by choosing Heading number under the Insert reference to drop-down menu.
The section can now be reached by holding the Ctrl key and clicking on the section number.