So pick one of three things.
Something you see that your character likes, something they dislike, or something your character could easily misinterpret.
Walk up and talk about this thing.
For example my racist Miqo'te might walk up to a highlander and go, "Hey, we don't like to see your kind in the city, why don't you go back to your camp, filth."
Or walk up to an attractive character and go, "Yes yes, very nice, how much?"
Both of those will certainly open the door for more conversation.
Something you see that your character likes, something they dislike, or something your character could easily misinterpret.
Walk up and talk about this thing.
For example my racist Miqo'te might walk up to a highlander and go, "Hey, we don't like to see your kind in the city, why don't you go back to your camp, filth."
Or walk up to an attractive character and go, "Yes yes, very nice, how much?"
Both of those will certainly open the door for more conversation.