Please answer this question...I need ur help!!?

I really want to meet famous ppl but i dont kow a way I could I want to meet Demi Lavato ..Selena Gomez ...Debby Ryan and all those ppl mostly the cast Wizard of Waverley Place but i dont know how. I want to know when there going to come to new york city or New jersey if any body knows a website that tells u this info. pllzz plzz tell me! :D