Thank you for reaching out to us. You can change the font family via Theme Options > Typography > Body and Content. If the Font Manager is disabled you can choose either system fonts or Google fonts. However if the Font Manager option is enabled then it lets you assign your own font selections set in the Font Manager. You can enable / disable Font Manager via Theme Options > Typography section (see screenshot)
To learn more about Font Manager please see https://theme.co/apex/forum/t/font-manager/101
Hope this helps!