Ask HN: Help a windows SRE/DevOps engineer transition to a linux shop

Yes, shoot me, but I've been on a Windows SRE setup for some years and my next move is likely to a Linux shop and I'm quite worried about my lack of OS experience.

I've got a VMWare Ubuntu setup and an EC2 machine to play around with which I try to practice on just to get the hang of basic operations on navigating the terminal. What are some advanced commands I should be fluent with and will save my ass when firefighting? Surprisingly finding a lack of decent tutorials on this "ramp up a Linux newbie SRE/DevOps".