First.... and don't feel bad if this is the case...... Is the engine running? The engine must be started for the headlight relay to provide power to the headlights. If the engine is running and you don't have headlamps try putting the high beam on and look for the blue indicator on your instrument cluster. If you see the blue indicator you may have bad bulbs.
If all that Motogiro mentioned is OK...
It only takes one broken wire to take out the headlights. If you have a multimeter (or something like it) you could check if you have any power at the bulbsockets and work your way back. Alternately try to jerk/twist the cable loom going out to the headlights a bit (when engine is on) to see if it makes a difference.
I had a flickering in my low beam but high beam was OK, checked the wiring and the horn wires had rubbed and worn through the insulation, re taped and I thought all was ok. issue started again and I finally found that the plug on the actual lamp had been shorting and the plug had melted. when ever the bars were slightly turned the lamp would short out. Ended up cutting the melted bit of the plug off and crimped a new spade bit connector and insulation. Problem solved. But it was not obvious and it took me over 6 months to finally track down the issue. I just kept poking the wiring til I could replicate the problem