https://mystery.knightlab.com/ to learn SQL
https://github.com/phyver/GameShell/ to learn unix commands
https://learngitbranching.js.org/ to learn git
https://www.unixgame.io/unix50 to learn unix commands
https://ofrak.com/tetris/ to learn ARM assembler instructions
https://sadservers.com/ solve different IT tasks
https://labs.iximiuz.com/ to learn dev/container
https://overthewire.org/wargames/ to learn cybersecurity
https://www.root-me.org/fr/Capture-The-Flag/CTF-all-the-day/ security capture the flag