At the simplest level, it looks like you might be dealing with shyness or social anxiety if you have trouble talking to strangers.
So I will play.
1. Tell me what is your favorite movie, book, TV or song -- and why.
2. Was there a time when you were ok talking to people? If so, when did the difficulty start? How do you feel about talking to people you know?
3. What was the last meal you ate?