How to speak when you meet the leader for the first time? I am an introverted person, and I am not very talkative. Please help me.

Since you went to his house, it means that you have a deep personal relationship. In your heart, don't take him as a leader, just be an elder you respect. Go to the door. As for speaking, you don't need to find too many topics, just give your parents a hand, talk less and listen more, and be diligent, which will be more pleasing. If you have a purpose, you might as well bring it up when you are happy.