Try the following:
http://forum.graphene-theme.com/feature-requests/random-front-page

Front Page Display

https://developer.wordpress.org/themes/basics/template-hierarchy/#Front_Page_display

If you wish to manually edit the front page, create a file in the document root, theme folder called front-page.php, this page takes precedence over any other file created for the front page. Note, the file will be empty when you created it, as such your home page will be. Best thing to do is copy another file over and then edit

/var/www/vhost/staging.goodfood/wp-content/themes/trance/front-page.php

https://wordpress.org/support/topic/how-to-display-a-random-page-in-a-static-front-page