You can set the blog typography options using WordPress Customizer. Select Appearance>Customize>Typography Settings.
In Typography Settings you can select the fonts for the heading, the post content and the navigation & Buttons fonts of your blog.
There are over 800 fonts available from Google Fonts Library.
There is also the option of selecting different language character sets, in order for the blog to display properly for non-latin characters in mobile devices.
Please note that not all of the fonts are available for every language character set.