First divide the file into several parts, and then insert headers and footers in each part as needed:

1. Open the Word document window and switch to the Insert ribbon. Click the Footer button in the Header and Footer group, and then select the Edit Footer command in the Footer panel that opens.

2. Edit footer command

3. When the footer is being edited, click the "Page Number → Page Bottom" button in the "Header and Footer" group of the Design tab of the header and footer tool ribbon, and select "Ordinary Numbers 1" or other page numbers from the list of page number styles that opens.

If you want to add a page number to the header, do the same as above.