If you have never used a timing light before, here are the basics. A timing light, or timing gun, emits a strobe light beam in sync with the engine’s ignition system. Specifically it matches the firing of one particular spark plug that has been predetermined to be at a set position under ideal conditions. Short version: it matches your engine’s rhythm. Exercise caution, read the light’s instructions, and use common sense. Take care not to let the light’s wires get tangled in the moving parts under the hood (fans, belt, etc.).
Usually a timing light has two leads (wires) with clips for the positive and negative battery terminals, and an “inductive” pick up that clamps around (not on) the number one spark plug wire. Your timing light may be different - read the instructions that came with it or ask somebody who knows about such things if you’re unsure. The number one spark plug is located toward the front of the engine on the side opposite the battery. If your car is left hand drive (North America for example) then it’s on the front end of the passenger’s side of the engine. If your car is right hand drive (Australia, New Zealand, Japan, or the UK for example) then it’s on the driver’s side. Attach the timing light to the plug wire remembering that it doesn’t actually clamp on the wire, it fits around it.
When you pull the trigger on the timing light you’ll should now see a strobe light effect. Taking care not to allow the light’s wires to get caught in the cooling fans or drive belt, aim the light at the crank pulley and pull the trigger. You should see a small mark on the pulley that corresponds to a scale on the engine block behind it. From this point on follow the procedures in “How to set the timing“.