Since years I do backup on the weekend.
I use borgbackup to copy my stuff from several machines to a backup machine.
AND I use borgbackup to copy that same stuff to a separate drive. Why? Because the backup machine is prone to over voltage damage. I have some protection, but I did loose a DSL Router (frizbox) due to lightning, which induced a surge in the phone line.
Fortunately I did have a configured, 2nd hand fritzbox in the cupboard, just for exactly this day! So, backup can also mean replacement for VeryImportantPlastikhoused hardware items :)
That being said: I do have a VeryImportantPhlashdrive, a usb stick, with my key material, journal, and a few more things on an encrypted partition. And of course, I do have TWO replacement flashdrives which get synced once a week, too. I have needed the backup only once so far, but I was sure glad I did loose only three unimportant days of journal.
So. Get going! There's free lemonade if you get thirsty along the way.