i have two black children we adopted. 19 year old daughter, 17 year old son. They have both been raised in Utah since they were infants by two fairly typical lds white parents. What I can say as an observer of these conversations is that treat them the same way you would any non black person. You would be AMAZED at how often guys in their 20's and 30's when introduced to my son get louder and more demonstrative and almost always call him "brotha". And yes, this has happened on multiple occasions where he was with a white friend and the person greets the white friend similar to how they greeted me. Also, my daughter has moved to St George for school. She works as a cashier and people have these really awkward conversations with her all the time! My point is: If you normally chat with your cashier, ask people of color the exact same questions as you would if the cashier was white! When introduced to people of color, stop acting weird! Just greet them the same way you would any one else.