After you click on 'receive', then click on 'create request'. You can leave the BTC or USD blank if you do not want to send the amount the person should send to you, you can do that while communicating and tell the person the amount he should send. After you click on create request, you will see the address QR code and you can see where you can copy the address at the lower left side.
If you want to see the address instead of the QR code, click on the QR code and the address will appear.
If you want to send coins, click on 'send', place the camera on the QR code. But if you copied the address instead, then click on 'paste from clipboard, which is seen at the lowest middle part.