You can use File > Save As and save as a template. You can give the template any name you wish.

The default template when you create a new document is the Normal.dotm template. That template should not have any text in it, including page numbers or headers/footers.

You can, using File > New and going to your own templates, use any template to create a new document. You can double-click on any template when in Windows Explorer to create a new document based on the template.

You can put a Windows shortcut on your desktop to any template and use that to create new documents.

Here is my article about Templates in Microsoft Word. An older version of that can be found on the Microsoft website.

You can easily add an icon on the QAT to create a document from your custom template. See my Add-In for an example of how this can be done.
Easy New Document Template Package
That has an icon to a macro that was recorded from using the template to create a new document from File > File New.
Modifying the Quick Access Toolbar (QAT) in Microsoft Word

You can also change how Word acts when you tell it to start a new document and have it use your custom template. I have a free Add-In that does this. You could look at that.
Letterhead AddIn(s) - Default New Document
That leaves the Normal.dotm template without any text for the other things that Word needs but lets the icon for a new file or Ctrl+N or just starting Word to have your template as its base.