To do any scripting or server side programming you are going to need to take a look at the command line, also sometimes referred to as the terminal. Working in the command line is also a great way of gaining respect from your friends for your mad tech skills. There are many fun tricks you can play with it.

This is a great set of tutorials to get started on familiarizing yourself with terminal commands. I recommend spending an hour of two going through these introduction ones so that you get familiar.

Absolutely essential terminal commands are:

pwd - print working directory
hostname - my computer network name
mkdir - make directory (follow mkdir command with the name of your new directory)
cd - change directory (cd followed by a path will take you to this location. cd followed by a directory in the location where you are will take you to this folder. To go up folders type cd ..  to go up two folders follow cd with ../.. 
ls - list files and directories of your current location
rmdir - remove directory (follow this with the directory name you want to delete)

And for some fun:

say - gets your computer talking, follow with a phrase or word

Be careful, from the command line you can do many more things than from a finder or GUI. It is possible to delete and move system files in ways that can break your OS. Make sure you think about what you are doing and ask me in class or via the code forum if you are worried about something you are trying to do.