Have you setup the cron job for moodle? That's outside of Moodle and is done @ operating system level.
https://docs.moodle.org/310/en/Cron
You might be able to get to the admin screen for cron related settings by going directly to:
https://yoursite/ admin/settings.php?section=sitepolicies
and
admin/settings.php?section=sitepolicies
'SoS', Ken