By default, theme uses Google fonts. In case, If you want to change font to any other Google fonts, Please have a look in the head part of the webpage and you will find this tag:

<link rel="preconnect" href="https://fonts.googleapis.com">
<link rel="preconnect" href="https://fonts.gstatic.com" crossorigin>
<link rel="stylesheet" href="https://fonts.googleapis.com/css2?family=Inter:wght@400;500;700&display=swap">

To change the font, first go to Google fonts, choose your desired font and use the generated code.

After changing fonts you need to update font families in _variables.scss or override in _user-variables.scss file

// Font Families

$font-family-base:           'Inter', sans-serif;
$font-family-heading:        'Inter', sans-serif;
  

If you want to use custom fonts, remove above section completely and visit Self Hosted Fonts