Easiest thing to do is to create a custom template with your header/footer and use that to create your document. Templates in Microsoft Word

Otherwise, in Word headers and footers are separate items on the same document layer. Page numbers inserted at a location other than the current location are also on that layer.

You can save your custom header as a header Building Block and your custom footer as a Footer Building Block. It is possible to attach a keyboard shortcut to a building block. Note that when you use a header or footer building block it replaces the current header or footer. Automated Boilerplate Using Microsoft Word

You could also record a macro implementing your header and footer and attach a keyboard shortcut to that macro. This would require that the macro be stored in a template that is trusted to run macros by your Trust Center settings.

Realize that as your documents become more complex, so do the header and footer settings. There can be multiple headers and footers in documents. Header/Footer Settings Recap