Please accept my condolences on the loss of your father.
If dad had a will then you will eventually be provided a copy if your step-mother ever submits the will for probate. She may not though. What I would advise based on these facts alone would be to file a Petition for Administration (which is very similar to probate, except administration is the word used when someone dies without a will). This will force your step-mother's hand to either produce the will, and disclose dad's assets and if they were in joint name, etc. Your mother may believe she knows dad's wishes, but unless he had a will then the laws of the state of New York dictate how dad's property is divided.
