You awaken in a sleeping pod in the Aperture Science Enrichment Center.
Start a New Game
To start a new game, choose New Game from the title menu.
When you first awaken, you will see a countdown on the wall. You won't be able to go anywhere until this countdown has finished, so just listen to the computer voice (you can go to the menu to enable Captioning if desired) and wait for the countdown.
After the countdown, an orange portal will be created to let you out of the relaxation cell. You can see yourself through this portal. If you turn right, you will see a blue portal outside of the relaxation cell, under the clock on the wall. That is the other end of the portal.
Go through the orange portal and follow the path to an open door. Go through it and it will close behind you. After a moment, a weighted storage cube will fall from a tube in the ceiling. Go to the cube and pick it up (the button to press will be displayed on screen) then go to the big red button in the floor and drop the cube onto it. The next door will open, and the computer voice will explain that the incandescent particle field in front of the elevator will destroy any items that you try to bring through it, such as the weighted storage cube that you used to push the red button.
When you are ready, go through the particle field and enter the elevator, which will start moving after a moment, taking you to the next level, Test Chamber 01.