You can shoot the target whenever you want, as Falconflyer said but the good shooters shoot as fast as they can. Just point your gun at the upper edge of the trap house, call pull and, as soon as you get a hard focus on the target, pull the trigger. As a beginner, just concentrate on seeing the target clearly before you shoot. Don't worry about 1 second or 2 seconds. The target is travelling about 70 ft/sec and the shot is going about 1200 ft/sec. No need to rush. It just seems fast.