This is a non-comprehensive catalogue of some relevant distribution (operating systems) of Linux. You do not need to know all of these, this is just some Linux-related resources for reference.
The Great Family Tree(s)
You can view the historical tree here, but be warned it is huge, you’re going to need to zoom out.
https://upload.wikimedia.org/wikipedia/commons/a/ad/2023_Linux_Distributions_Timeline.svg
https://distrowatch.com/dwres.php?resource=family-tree
The Linux Distribution Newsletter
This website hosts news articles of new releases for various Linux operating systems. It’s not required to know about all of them, but if you’re curious you can take a deep-dive here.