To use QR codes you must have a smartphone or Ipad equipped with a camera and a QR code reader/scanner application feature.
You can download this from the app store under 'QRReader.'
When you have the tools you need, you can start scanning.
Do your best to steady your hand while the QR code is centered on the screen.
As soon as it is done scanning, my link will come up with a website about space that is great for kids learning.
Enjoy and have fun.