Police officers frequently begin questioning potential suspects immediately upon initial contact. Questioning does not necessarily indicate that anyone is detained or arrested. Does that mean that you do not have to cooperate with the cops? In short, you have the right to remain silent, at least initially. There are pieces of information that are pertinent, and you should share with the questioning officer; however, you do not necessarily need to share any other information beyond those initial questions.
What Is Initially Required
Maintaining a polite demeanor throughout the experience often goes a long way toward helping your case. Being polite does not mean helping them build a case against you, however. If you are in a public place, the only information you are required to give is your name; which is only valid if the officer suspects you have committed or are committing a crime and they announce themselves as police personnel. Cops may also ask you to give your address and a reason for your behavior. You do not have to answer either of those questions legally.
Your Fifth Amendment Rights...