Areas that single cam bows excel at are smooth draw, and lighter weight. Some of the current Single cam bows weigh in at around 3.25lbs. Other advantages of the single cam are easier tuning, flater arrow path when the string is released. With two cam and wheel designs if the wheels or cams get out of sync then accuracy suffers because they impart un-equal forces to the arrow, kinda like a push me pull me trying to go two differant directions. Since the introduction of the single cam concept many inovations have come along, such as weighting the perimitter of the cam which is claimed to reduce vibrations.
Regular practice is the key to being a successful archer.
If target are you desire then visit a local Pro Shop and join a league Where you will get exposure to several different types of target shooting and methods.