Security and pen testing distribution
Kali Linux is a profession security Linux distribution. I have just installed 2019.3 yesterday so will need to do some experimenting before commenting further. Lots of useful packages for security and security audits. I have also joined their IRC channel on freenode #kali-linux.
If you want to learn about cyber security this is probably a good place to start. The website has lots of resources to help you get started and move up to what looks like quite an advanced level, including details on certification.
Please feel free to discuss further on friendi.ca