Look into the Word object model and how Word configures things.
Word Doesn't Know What a Page Is

You may want to have a style that is (1) unnumbered, but (2) at the top level of a multil-level list. Set that style for Page-Break before formatting and use it to start new pages when you want. Set level 2 numbering to restart after each level one instance.
How to create numbered headings or outline numbering in Ribbon Versions of Word by Shauna Kelly