After the intro scene is completed, you can press the green Start button at the bottom of the right side of the screen. You can then choose whether you want to play in Practice or Normal mode.
If you choose Normal mode, the next question you will be asked is whether you want the difficulty to be Easy or Hard. If you click Easy, you will then see the game beginning. After your character walks to a car, you will have 10 seconds to use your arrow keys to enter the pattern being shown on the screen.
If you're successful, you can then use the arrow keys to start driving the car. Just be sure you don't crash, because that will get the police's attention and cause you to end up being busted!