If you are a girl,never use the same "good manner for the hight class" as you were used to at home. you would better watch and imitate the actions of an average American girl: ready to smile when somebody greets you,willing to boy answer any question any boy asks you. do not turn and put up in rage when a boy approaches. he as well as his friends would be surprised. that would make them consider you to be not a kind of social animal.