The Windows activation key is printed on the accessory box included in the packaging.
Maybe your display isn’t plugged at the right video output : you have to connect it to the graphic card (horizontal connectors)
New generation computers don’t have VGA output anymore. If your display has HDMI, DVI or Display Port, we recommend that you change your video cable to use one of these input. Otherwise, HDMI to VGA adapters are available on the market.