Does Interpol operate in the U.S.?
That depends upon what you mean by “operate.” AFAIK, Interpol doesn’t actually do any active law enforcement - there aren’t any Interpol agents driving around in cars with flashing lights, chasing criminals. Interpol is primarily an information-sharing organization, and the U.S. is a member, along with 180 other nations.
Interpol doesn’t really “operate” anywhere. It’s an organization for sharing intelligence about criminal activity, tracking international fugitives, and for law enforcement agencies in various countries to communicate with one another.