No prob...

It's a special strobe light that goes off with the spark plug. You shine it at the timing mark so it freezes the position of the timing mark at the exact instant when the #1 spark plug fires. You watch that as you adjust the spark timing.

Check AutoZone or someplace like that. It looks like a goofy flashlight with a pistol grip & a bunch of wires to connect to your car.

The distributor controls exactly when the spark plug fires. The idea is you're adjusting the distributor so it fires at the correct time.

If you don't do that you'll either get bad gas mileage, or you'll fail your next smog test. Or possibly (but not likely) you'll burn a hole in a piston.

Look for a DIY on adjusting spark timing, someone's probably already written some good instructions.