If my parents dont give me my birth certificate and passport at 18?
Your parents paid for your birth certificate and are under no obligation to give you one. Feel free to get your own. Your passport is a different story and generally it is illegal for anyone except a passport control officer to take your passport. If you do involve the police, be prepared for the consequences, which could include a criminal record for your parents. You might regret it. Instead you might consider just getting a new birth certificate and then applying for a passport on your own. You can tell the passport agency that your passport was taken from you and you need a replacement.