man [command name]
man is a manual program, and my best friend.
ls
list files in current dir
mv [source] [destination]
Move files, also used to rename files.
cp [source] [destination]
Copy files
[b]sudo[/b] [command]
sudo, or superuser do lets you run a program as your current user, as if you were the root user.
sudo !!
Allows you to run your previously entered command as root.
sudo apt install [package name]
Allows you to install programs from the command line, use apt-get for shell scripts.