Finding my father

So I'm 27 years old I don't know who my father is I don't know his name or anything I have very little details on him. My mother will not give me any information because she says she isn't ready. Well I am ready to try and find out who my father is and I have no idea where to even start. His name is not on my birth certificate, once my mom found out she was pregnant she kicked him out of my life. If anyone could help me or guide me in a direction on how to start that would be great