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

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

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)

Move, this is how you move something from here 
to there. This is also how you rename something 
even if it's in the right place.

Copy. Add -r to make it recursive, else it 
won't copy directories because it won't 
descend into them.

present working directory. this 
is how you get it to tell you where you are 
in the file system.