* You'll have a set of Voltage ranges on your meter. Select the one that has a greater than 120 volts scale.
* Be extremely careful with touching any wires.
* The outlet has the White wires going to one side and the black wires going to the other side.
* You can insert your voltage probe into the outlet slots. Make your first measurement there. There are two slots side by side. The other slot is for the ground.
* Let me know...