Edit "Normal" Text
This video will show you how to update Normal text.
The majority of your document's text is "Normal". This is the default body text. I'll show you how to update the Normal text throughout the entire document.
One way to do this, is to format one section of text.
Then, in the Insert tab, in the Styles group, right-click the Normal style, and click "Update Normal to match selection". This will update the Normal text throughout your document.
Alternatively, you may edit the style directly. Right-click on the style, and click Modify.
Make your formatting changes, and click OK.