How to change Google Fonts
To add more Google fonts besides the ones Hello! Pro comes with or to remove them, edit the theme’s functions.php and look for this line:
wp_enqueue_style( 'google-font', '//fonts.googleapis.com/css?family=Comfortaa:400,700|Lato:400,300,300italic,400italic,700,700italic', array(), CHILD_THEME_VERSION );
Add or remove google fonts in the above line. Fonts are separated by the pipe (vertical line) symbol.
You can get the font-family and see the various font weights on Google Fonts website.