Linux From Zero - For People Who've Never Used It and Are a Little Scared

What Linux actually is, how to find your way around its filesystem and install software, how users and permissions work, and how to start and read background services - for someone who's never touched it.

1. What Linux Actually Is Linux is a kernel; Ubuntu, Fedora, and Debian are the same kernel with different packaging around it. That one idea explains the distros, where Linux runs, and what free and open source means.
2. Getting Around The Linux filesystem isn't C:\ and Program Files - it's one tree where /etc holds config, /var holds logs and data, /home holds your stuff, and software is installed from a package manager (apt/dnf), not downloaded installers.
3. Users, Permissions, and sudo Root is the all-powerful admin user you don't log in as; sudo lets your normal user borrow root's power for one command; and every file's rwx permissions for owner/group/others decide who can do what.
4. Services and Logs A service (daemon) is a program that runs quietly in the background; systemctl starts, stops, checks, and enables them; journalctl shows their logs - plus a first-day snags cheat-card for when things go wrong.