I have begun learning security skills on the TryHackMe website and have completed two rooms. In my opinion, it is the best site for acquiring and practicing security skills so far.

• Nmap Live Host Discovery

• Linux Process Analysis

And several years ago, my VPS is hacked, so I spent lots time to analysis problem, and fixed by analysis the process.

Nmap Live Host Discovery

https://tryhackme.com/r/room/nmap01

Linux Process Analysis

https://tryhackme.com/r/room/linuxprocessanalysis