What website do i have to go to to book a famous person at my party

There isn't one website for everyone. It depends on who you want. You need to get in touch with their manager. Please keep in mind that it won't be cheap. You need to get in touch with the famous person's manager. Furthermore, famous people aren't just party-entertainers. Chances are they won't want to just show up for your party because you want them to, so unless you're willing to pay thousands of dollars for their time, they won't wanna be there. They're only human after all.