For years I had MS office 2003 now I've updated with a new computer (from Vista to Win10)
And I now have MS Office 2016 so I'm still pretty new to how things work. In Word, I've figured out a lot of it (love the little box at the top that asks what I want to do! very helpful!)

I have a manuscript that I opened to work on in Word and found a design template (minimalist) that I like a lot. But I want to change the font size for the body (not the Title or Chapter Titles) and I'm not sure how to do that. Is there a way?

This is a very large document and would be a pain to have to select all the text in each chapter, one at a time and apply a new size. I hope I don't have to do that.
Thanks for any suggestions.