Hello Joan,
If the available fonts family did not work for you. You need to add the custom fonts. Adding custom font’s is somehow complex for you. You need to download that font’s, enqueue that fonts on functions file and call that font’s on style.css. It’s really a complex job. We recommend you to use the available font family on Appearance > Customize > Layout/Design Options > Font Family Options.
If you need the additional, please take a help from the blog post here. Or please try this plugin once.
Regards
Acme Supports