how to add a font to my header?

Hi all, I recently installed “google font” plugin but it doesn’t allow me to change the font type of my menu. I am using the Photocrati theme and I thought it might be in header.php but didn’t find anything related to font types, sizes, etc. I then checked my css and it’s virtually empty.

I have been doing some reading and I think I need to add a line of code to my css (I could be wrong) but I dont know what it is. The Google Font that I thought was interesting is called “Dawning of a new day” and my site (still a work in progress) is https://www.replayimage.com.

any help is appreciated.