I’m not a big fan of Arial 11 pt font, the default font for Google Docs and perhaps you aren’t either. If so, here are two ways to change the font style and size. If you want to change the font for the document you’re working on and that's it, go to the font drop down menu in the toolbar. Easy enough.
If you find yourself using a favorite font for all your documents, then follow these steps to set a default font style and size for all new documents. No Comic Sans, please!
First open a new document and type a word.
Highlight the word, select the font and size you want, and click "Normal text" on the toolbar.
Click the arrow on the right-hand side and click on: “Update ’Normal text’ to match”.
Now back to the Normal text box again, go all the way down to Options and click on “Save as my default styles”.