You turn the ignition key to ON, making sure the "KILL" switch is in the run/down position and press  the starter switch and starter motor does not turn over the engine.

I you hear a "clicking sound," this can indicate the battery has low voltage (less than 12.0 VDC recording on a voltmeter).  Recharge battery.  You can try jumping the battery from another bike.  If jumping from a car or truck that have a heavier charging system (not recommended, but sometimes your only alternative), touch the ground wire clip to the car/truck negative terminal as the starter button is pushed.  Remove the clip as soon as the engine starts to avoid damage to the bike's electrical system.

If the lights come on, but then go out when you press the starter switch, it's likely the battery has a shorted cell.  If it's a shorted cell, you must replace the battery.