This is a tall order. You are looking for a book.

1. You need a custom template that all documents use to start. They start with File > New, not by opening the template. Templates in Microsoft Word
2. The template has numbering attached to styles following the procedures set forth here: How to create numbered headings or outline numbering in Ribbon Versions of Word by Shauna Kelly
3. The template has different first-page header set.
4. The continuation header has a StyleRef Field that refers to Heading 1 and a second one referring to Heading 2.
5. Each team's report starts with a Heading 1 and that is the only Heading 1 in that report. Heading 2 gives the main points.
6. All formatting is done using Styles.

You can use editing restrictions if needed.


"Section" is a term of art in Word -- jargon. It may or may not relate to what you mean by section but controls layout, headers and footers. Each report can contain one or more Word sections. Sections / Headers and Footers in Microsoft Word 2007-2013