***How to create a FORMATTING template for Microsoft Word 2013?***

You can certainly create a template that contains styles that use the font and paragraph formatting you want. You can then insert each of the existing documents into a new document based on that template. But you will have to apply the styles to the text manually unless the documents are already formatted with corresponding styles that will be automatically updated when a new template is attached.

That is, all the text in the documents that is in the Normal style (without direct font or paragraph formatting) will be updated to your modified definition of Normal when inserted into a new document based on your template. Ditto for Body Text, Block Text, Heading 1, Heading 2, etc. But if the entire document is in the Normal style with direct font and paragraph formatting, you'll have to clear all the formatting and then apply the appropriate styles (Body Text, Block Text, headings, etc.) to the paragraphs.