U.S Referee?

Hi guys ıf any of you are referee in the usa. I would like know some information from you. I m a student in turkey. I study at sport manager depatmant of my university. So after I graduate from my major within two years. I would like attend u.s. soccer fedaration for being referee. I have a referee licence down here for two years. I mean I m licenced referee in my own country. what I wnat to know learn is exactly where I m gonna apply for this attempt. I will be waiting for useful information from you. Let me know what I m supposed to do until I gruduated from my major.