If you are stopped by

police or immigration:

Ask Officers "Am I being detained?"
If you are not under arrest, you have the right to calmly leave.
If the answer is yes, ask "what reasonable suspicion do you have that I am committing a crime?"
You have the right to a lawyer if you are arrested. Ask for one immediately.
You have the right to remain silent. Refuse to consent to a search of yourself, your car or your home.
Regardless of your immigration or citizen status, you have constitutional rights.

IF STOPPED FOR A SUBWAY SEARCH BEFORE ENTERING THE STATION

You have the right to refuse to be searched and all that it means is that you can’t enter THAT station, you may walk to the next station and carry on. YOU DON’T HAVE TO BE SEARCHED.

IF STOPPED BY A SCHOOL “SAFETY” AGENT

Remain calm as to not escalate the situation.
Do not speak about the “incident” to the SSA, anything you say will be used against you.
Remain silent
Ask for a lawyer and your parent or guardian
Remember SSA’s name and badge number.
If an SSA attacks, harms, or violates you in any way, remember as many details as possible and look around for witnesses who can later help you corroborate your claim (also where video and cop watching helps to make your case stronger)
If arrested, ask for your parents and a lawyer and REMAIN SILENT.

If you need legal assistance go here.

For more info about your rights in NYC see here.