GUIs change, but the command line is eternal. Memorize these 5 commands and a long and happy life awaits.

$cd
change directory.  This is how you move 
around the file system.

$ls
List, or tell me what's in this directory.  This has a 
huge list of useful modifying flags, such as -l (long, 
tell me the size, ownership, and permissions on each 
thing in here too), or -a (all, as in, show me hidden 
dotfiles as well)

$mv
Move, this is how you move something from here 
to there.  This is...