You can change general font settings for the store through the Themes Editor in your store Admin. This
enables the shop owner to edit the stores entire colours, fonts and
appearance while viewing a preview on the right hand side of the page. This is done via the 'general' tab and then 'styles'
If you wish to change specific fonts for products and the home page, use the Rich Text Editor that is provided. Select which font you wish to use for each individual section of your storefront.