If you are familiar with running a Linux in the Debian family, you are already 99% there to running a Pi. If you have Linux, but not Debian, you're probably 95% of the way there and have to learn a different update/upgrade/install suite of console commands or their GUI layer on top of it.

If you're not familiar at all with Linux, a Raspberry Pi or similar computer is excellent to learn it on, since the cost of accidentally destroying the operating system environment is reimaging the card that contains it with something fresh and going at it again.

Running backups? What did you have in mind for it?