It really depends. I work for a large company and we use Ubuntu, Oracle, RedHat, and SLES. We were moving from Oracle to Ubuntu but now we are going back to RedHat.
Currently we deploy like this:
Ubuntu: PostgreSQL, web servers, some engineering workstations, and big data
Oracle & RedHat: web servers, security applications, and network systems
So just having a fundamental understanding of Linux and you will be fine
SUSE: SAP and HR software
I switched to Firefox years ago and don't regret it. There are some sites that don't play nice with FF, but for the most part it works better than chrome.
At work we are starting to transition to Ansible from chef and other homegrown solutions. So to learn Ansible I added awx to my home lab and now have playbooks for almost all of my devices. Going to format a Pi again soon and see if everything works as intended
It really depends. I work for a large company and we use Ubuntu, Oracle, RedHat, and SLES. We were moving from Oracle to Ubuntu but now we are going back to RedHat.
Currently we deploy like this: Ubuntu: PostgreSQL, web servers, some engineering workstations, and big data Oracle & RedHat: web servers, security applications, and network systems
So just having a fundamental understanding of Linux and you will be fine SUSE: SAP and HR software