Add a card on your Android™ Phone:
On your Android™, download the Google Pay™ app. Open the app and follow the instructions to enter your card information. Make sure your NFC service is turned on (this can be found on most phones under settings). Many phones have it turned on by default.
When its Time to Pay:
When it is time to pay, unlock your phone and hold the back of your device close to the credit card terminal. Hold your phone for a few seconds.