Hello and welcome!
I would say that this is a quite difficult first project. Maybe even too difficult.
I think you should complete a few of these tutorials and see if you have an idea on how to implement the project. (Both what hardware to use and how to program the Arduino)http://arduino.cc/en/Tutorial/HomePage
The Knight Rider is a very popular first project.
Make a nice case with some leds, and have them chase each other in eternity :]http://arduino.cc/en/Tutorial/ForLoop
Whatever you choose: Remember to have fun, and report back to us!