Go to Appearance > Customize > Theme customization > Typography
You can choose custom font families and settings from Google Fonts list.
If you experience issues with accented letters or non-English characters, make sure your language is supported by the font you choose on http://fonts.google.com.
Click Publish to save changes.
As not any dress fits good with any person, not any font fits good in any website. Some font families, in fact, have very different spacings, vertical alignment, horizontal kerning or rendering result.
This means that you may sometimes think a font is great, but it may look all smashed while setting it on your site. If you want some professional help with the choice of font combinations, please feel free to contact our support.