You are required to identify yourself to a police officer who asks (per Hiibel v. Sixth Judicial District Court of Nevada). You are not required to show them identification documents. There is no good reason to do so. Do not do this. Tell them your (real) name. Certain states (not California, mind you) may have state laws requiring you to give the police such information as your address and date of birth; the Supreme Court has not ruled on the legality of these laws. I would probably not comply, but that one is up to you. Do not talk to the police. Do not assist them with any investigation -- you are not required to, and providing false information is an easy crime to get booked for. Do not answer their questions. Do not allow them to search you. There are nice cops who are just doing their job, but the potential downsides are not worth it. "Am I being charged with a crime? Am I free to go?" Those are the only things you should say to the police.
And if you get arrested, remember that, per the reprehensible miscarriage of justice in Berghuis v. Thompkins, you must explicitly invoke your right to silence in order for the police to stop questioning you. Police interrogations are so effective that perfectly innocent people have been known to sign confessions after extended interrogation sessions. Tell them you are using your right to silence, and that you will not answer questions without an attorney present, and do not say anything more until that attorney shows up.
Know your rights, and insist upon them. Do not cooperate with the police beyond strict necessity.