Getting comfortable with Linux?

While I did see similar posts I think my question warranted a separate thread. I'm looking for resources to help become more comfortable BUT from a network management/penetration testing perspective. I just started my network management/ security bachelors program and have only had one 100 level Linux class. The class was basically following lab instructions step by step and we really didn't learn anything at all. I'm looking to get a better handle on Linux but not just for casual use. Any tips? Thanks!

commands cheat sheet:

zsh shell tricks:


linux file system:

file system permissions:

group access: