This example uses 2 LEDs and a switch to make an ON/OFF door lock. When the RED LED is ON then the door lock is closed. When you press the BUTTON, door will open and the RED LED will be off and the GREEN LED will be ON.
You will need the following parts:
1x arduino uno
1x arduino uno USB Cable
5x Jumper Wire
1x Red LED
1x Green LED
1x Push button switch
You purchased your Arduino kit from here
Ensure that the LEDs are the right way around, with the longer positive leads (anodes) to the left.