If you’d like to use other font than Google Font that are already available in theme in Appearance → Typography you can upload your own.
Install Custom Fonts – Host Your Fonts Locally plugin:
and then add this code in Customize → Additional CSS:
body,p,a,h1,h2,h3,h4,h5,h6 { font-family: "Your Font" !important; }
Don’t forget to replace “Your Font” with font name you want to use.