A courtship may be an informal and private matter between two people or may be a public affair, or a formal arrangement with family approval.
Traditionally, in the case of a formal engagement, it has been perceived that it is the role of a male to actively "court" or "woo" a female, thus encouraging her to understand him and her receptiveness to a proposal of marriage.
The dating cultures in different communities are thus considerably varied. Some people will be offended you asked them out because of your race or your perceived status.
Some people will be offended you asked them out because they will think you "objectified" them or they have been taught to view sex as a dirty thing.
Dating is actually a pretty recent phenomenon, in the grand history of civilization.
It wasn't until the 19th century that launching a relationship had anything to do with love and attraction.
It is best, however, to address professors and older persons with their title (Dr., Professor, Mr., Mrs., or Ms.) unless they ask you to do otherwise. We have communities where pre-marital sex can get you socially ostracized and marital sex is supposed to be for reproductive purposes only, and not enjoyed.We also have communities with sex clubs and weekly orgies where anonymous sex is common and encouraged.This also gives the people who would be interested in you the chance to say "yes," because most women in the United States are not comfortable approaching men, and in the more conservative parts, the social consequences of them doing so are especially pronounced.When I've done cold approaches in the past (always in bars and clubs), I've tended to open with "you guys seem fun, can I join you?