Im a cutie guy but im really shy to talk to girl how do i over the feeling of rejection and being shy?

im a cutie guy but i cant get the courage to talk to girl i have to let them talk to me 1st but sumtimes i want to go say what sup but im really shy what should i do to over come from being shy and im arfarid of rejection and i 1st really dont know what to say to a girl if i were to walk up too her how would i evern ask her for her number