To measure AC voltage for example on your engine’s stator, you first locate the two wires coming from the stator. Turn your DMM to AC Voltage. Place the red probe onto one of the wires, and the black probe on the other wire. You should read about 24 to 30 VAC.
Digital Multi-Meters come in two common varieties: Auto- Ranging, and Non Auto-Ranging. A non auto-ranging meter requires you to select a range of “sensitivity” for the given function you are using. For example if you want to measure resistance, you would need to select a range of up to 200 ohms, up to 20Kohms (20,000 ohms), 200Kohms, etc. An auto-ranging meter will automatically figure out the range and give you a measurement.