I don’t back up my drives, I replicate them.

There is a lesson about unnoticed data damage in someone’s future.

What happens when a software bug, ransomware, or hardware problem destroys or corrupts that data over days or months?

This Lemmy community has a great set of intro Linux lessons to get you started:

https://programming.dev/c/linuxupskillchallenge

The scheduling command for a one-time future run is the “at” command.