On the Fonts page, you will see a section dedicated to the free Google Fonts.
The top part of this section contains all the fonts you currently have activated, and the bottom section is a list of all free Google Fonts.
From the bottom section list, you can scroll through and find a font you like the look of, and click the little magnifine glass icon at the end of each font row to open the preview mode.
The preview mode will open as a modal popup showing you the name of the font, the category of the font, and all the variations of weight and style of the font.
You can also change the dummy text to see how a specific piece of text may look in this font. Once happy, you can hit the 'Activate' button in the bottom right of the popup
