You must be paid for every hour you work, even if that work occurs before or after your scheduled shift. If you work more than 40 hours in a week, your employer must pay at least 1.5 times your regular rate of par for hours worked over 40.
As of 12/31/18, the minimum wage in New York City is $15.00/hour for fast food workers, $15.00/hour for all other employers with 11 or more workers, and $13.50 for all other employers with 10 or fewer workers. If you receive tips, you may receive less than this amount if the tips you receive bring your hourly rate to at least the minimum wage.