@JenniferFavoros ...
I don't know how you would be able to change the font for all content pages within a Canvas course all at one time. (To be honest, I'm not sure if there would even be a way to change this with some back-end scripting. That's a bit beyond my scope of knowledge.) However, if you are editing content pages in your course, you can change the font page by page using the RCE (Rich Content Editor). When editing your page, select all the text on the page (Ctrl + A), and then in the RCE select:
"Format" >> "Fonts" >> "Georgia"
If you look at the HTML code after changing the font on a Canvas page, you'd see something like:
<span style="font-family: georgia, palatino;">
I believe this means that if someone's computer did not have the Georgia font available, it would display the Palatino font instead.
Of course, as you've seen from my first reply, someone could choose to set their own font in the browser preferences/settings...which *may* override the teacher's preference (though not 100% sure of this).
Hope this helps a bit. Good luck!