What is possible.
WHAT YOU CAN MONITOR
That the site responds, from an external service That specific pages contain expected content Certificate and domain expiry Whether scheduled tasks ran Whether backups completed Application errors, through your own logging
WHAT YOU CANNOT MONITOR
Server-level metrics, which are the provider's concern
WHAT CPANEL PROVIDES
Resource usage for your account Error logs Access logs
WHAT TO CHECK THERE
Whether you are approaching any limit Whether errors are occurring
WHAT TO SET UP EXTERNALLY
Uptime checking, from more than one location Alerting to somewhere independent
WHAT TO BUILD INTO SCHEDULED TASKS
A record that they ran, and alerting if they did not.
WHY
Silent failure of a scheduled task is common and invisible.
WHAT TO CONSIDER
Sending application errors to an external service that alerts you.
WHY
Otherwise nobody reads the log until a customer complains.
WHAT TO REVIEW
Resource usage monthly, against your plan.