There is a website called roadmap.sh which has both Skill and Role based roadmaps to learn how to program. There is no actual “SysAdmin” role path since our job can technically have several routes by itself.
I personally use Debian at my org, and found Python and Bash enough to automate small things that need to be done in a regular basis.
But if for example, you were a Windows SysAdmin you’d have to learn to use PowerShell ~ or VBS (idk if those scripts are still a thing)~ .