Respect people's boundaries please. Don't force yourself on people unless they're obviously willing participants.
People put extroversion/introversion as like this binary, permanent thing that cannot be changed. In reality I think it is a spectrum that changes throughout the day and the situation. Someone might be introverted at 8am on their commute, but a wild extrovert at 9pm in the bar. Don't assume, don't try to "help" people you know nothing about.