Is there a website that can tell you the new names to I guess "classify" people? Like the R word, or the N word or skin color or nationaility? For ex. Is African American still acceptable and so forth

I got my shit handed to me because I said someone is mentally challenged. But apparently where I work that is considered hate speech. Is there a place where I can read the new terms? Like do we call all people from South America something or is it like Spanish American or Mexican American and so forth?