If my stepmother died without a Will and was still married to my father but has 2 biological sons, am I entitled to anything?

Under NY law, when a person dies without a will, distribution of their property is governed by § 4-1.1 of the NY Estates Powers and Trusts Law, which states in relevant part as follows:

"Descent and distribution of a decedent's estate.
The  property of a decedent not disposed of by will shall be distributed as provided in this section...Distribution shall then be as follows:
    (a) If a decedent is survived by:
    (1) A spouse and issue, fifty thousand dollars and one-half of the residue to the spouse, and the balance thereof to the issue by representation.
    (2) A spouse and no issue, the whole to the spouse.
    (3) Issue and no spouse, the whole to the issue, by representation..."

Issue means children, which in your stepmother's case would include any children from the marriage of your father and stepmother, and any children your stepmother had from prior marriages or non-marital relationships (NY law provides that: "A non-marital child is the legitimate child of his mother so that he and his issue inherit from his mother...").

Since you stated that your stepmother leaves 2 biological sons, and assuming your stepmother is also survived by your father, the law of intestate succession would require distribution of your stepmother's property in the amount of fifty thousand dollars and one-half of the residue of her estate to the spouse (your father), and the balance thereof to her 2 biological sons. NY's intestate succession law does not include the intestate distribution of the property of a decedent's estate to a "stepdaughter", since stepdaughter is not defined under NY's intestate laws as "issue". 

Property that passes to your father as the surviving spouse under NY law, becomes your father's lawful property, after Surrogate's Court appoints an administrator of her estate & there is an administration & settlement of your stepmother's estate in Surrogate's Court (in the county where she resided at the time of her death).

Property lawfully inherited by your father as the surviving spouse, may be left to the beneficiary or beneficiaries designated by your father in his will, in accordance with NY law. If your father does not have a will, he will not have any control over how his property is distributed at the time of his death, and distribution of his property at that time would also be governed by § 4-1.1 of the NY Estates Powers and Trusts Law.