This chamber is another simple one to get you used to the concepts in Portal. Like the previous chamber, it has a single fixed orange end to a portal, but this time you must press a button to open the exit door.
If you look at the cube dispenser, it unfortunately drops cubes into a pit, which at first seems inaccessible. However, if you fire the portal gun at a wall at the bottom of the pit, then walk into the orange end of the portal behind you, you will end up safely at the bottom of the pit. Pick up a cube and return to the main area of the chamber, then put the cube on the button and exit.
Well done; excellent work. As part of required test protocol, we will not monitor the next chamber. You will be entirely on your own. Good luck.
—GLaDOS