Is 我去广州见朋友 or 我去广州看朋友 better for saying "I go to Guangzhou to see a friend"?
In this case, I think 我去广州看朋友 is the suitable translation for "I go to Guangzhou to see a friend"? 我去广州看朋友 usually means you want to see your friend there to see how everything is going with him.

Well, 我去广州见朋友 sounds that you want to meet a friend in Guangzhou, usually for some purposes(like business, talking about something, etc.)