If the new page is at the beginning, you could use the Different first page
option (File - Page Setup - Layout tab).

Anywhere else, separate the page with a Next Page section break (Insert -
Break - Next Page), then turn off the Same as Previous option in the
Header/Footer toolbar so that that new document section's header/footer can
be unlinked to other sections' numbering, etc.

If the new page is between pages that are to be numbered, you will have to
futz with the latter section's number to force it to resume correctly.

his can be complicated, but not impossible, so post back if you have
problems.