Points to remember
1) If your device is new then update the latestvgoogle Maps app from playstore
2) Make sure to turn on the location settings in your smart phone.
3) Go to the link given below and login with the same google account which you logged in on your smartphone.
4)Now click on the Locate button in the pc browser in which you opened the link
You can also erase or lock your lost device.
You can give a ring to your mobile which make your mobile ring for 5 minutes.