Find My Device enables you to find your phone if you lose it or you can lock it should it get stolen. To turn on Find My Device, you need to activate your Google account on your phone and turn on GPS.
Slide two fingers downwards starting from the top of the screen.
Press the settings icon.
Press Find My Device.
Press the indicator next to "Use Find My Device" to turn on the function.
Slide your finger upwards starting from the bottom of the screen to return to the home screen.