Look into Building Blocks including Cover Pages and AutoText.
Automated Boilerplate Using Microsoft Word

Word does not really see or use "pages" as a unit.

• Moving/Reorganizing Pages in Microsoft Word
• Word Doesn't Know What a Page Is

Rather than "applying a template" consider simply creating Word templates for what you want to do and creating new documents or templates based on those templates. "Template" is a jargon term in Word with a very specific meaning.

When creating templates for others, pay attention to Styles, [Quick] Style Sets, and Themes. They can make your creations much more useful and flexible.