The blank page could have no displayed or printed number if you want but simply be counted in the numbering.
If you use a gutter to allow space for binding, that, too will make a larger margin on the left for odd-numbered pages and on the right for even-numbered pages (the "real" number, not the displayed, calculated, number).

Also, a table of contents could be very useful to your users and would be very easy to create if you are using styles for your headings. If it takes up a single page, it could fill that otherwise blank page.

Generating a Table of Contents - Complex Documents
Understanding Styles in Microsoft Word
Why use Microsoft Word’s built-in heading styles? by Shauna Kelly
How to create a table of contents in Microsoft Word by Shauna Kelly