I am a son to an American citizen, I was born in Dominican Republic and came to the United States(New York)when I was 14 years old since then I am a Permanent Resident. When I was 17 my father applied for my citizenship with the N-600 form and I was denied because my father "didn't have my custody" so Now, I'm 19 years old I was told (by an Immigration Lawyer) that I am an American Citizen and all I have to do is go to a passport agency or postal office with my Father, the necessary documents and apply for my American passport. Now my questions are:

1- if my father doesn't have my custody how come he brought me to the United States to live with him?

2- if my father does not have my custody I can't become an American citizen and I have to apply for it?

3- If I apply for the passport and I get my passport, how and where or when do I get the Naturalization Certificate or Certificate of Citizenship?

Maybe try to contact Immigration?

actually, the banner ad across the bottom of your post for US immigration would probably be your best bet ^_^

First of all, you need to discuss this issue with your parents for all details info. Having a US citizen father doesn't always mean that you are US citizen. It depends on many factors...

Is your father a US citizen by birth or naturalization? If naturalized, was it before or after you were born? Were you parents legally married? Did your father report birth of US citizen abroad to US consulate when you were born? Do you have US birth certificate? How did you get to US? What type of visa was it? What about your green card? When did you first obtain it and when is the expiration date? Are your parents still married? Etc.

Just apply for a passport. If you get it by providing all of the information required, it means you are a citizen. You are then unlikely to need a certificate however there is another form that you can on the US immigration web page you can fill out and pay a fee and they will send it to you.