Here's how you can change your website's fonts:
1. In your site editor, go to the Design Tab.
2. On the menu to the left, go to the section called Font. You'll see 2 drop-down menus:
i. When you click on Suggested Fonts, you will see a list of fonts that best suit the theme you've selected. These are font families, which means that the font you select here could be applied to all the texts on your website, or only to specific texts. If your selected font gets applied to specific texts, then a font that compliments your selected font will be applied to the remaining texts.
ii. When you click on Custom Fonts, you can select from a wider variety of fonts for your website's heading and body.