I'm 17years old and I have never met my dad.
Him and my mom split up when I was only a few
Weeks old, and she didn't tell me until I was
13, and was led to believe another man
Was my father.
How can I find him?

For 17 years your dad has had the opportunity to find you. If he had any excuse to search you out, I'm sure he had ways to contact your mother to inquire about you.

If you have your father's name... then a search through phone directories might be a place to start. If you are not of the same name, but know his name, then same advice.

Be careful. He may have re-married, has a family that knows nothing of you. Your showing up on his doorstep might cause many entanglements.
Let your mother get in touch if you feel you have reached him.

If your father had siblings... brothers or sisters, then you might be able to find them... and him through them.
Tax records might cross-over... names with properties. A tax registery might be searched.
If your mother and father are divorced, then such court record might be searched.
You may have to go through a court clerk ---not necessarily a lawyer, to find such records.

You could advertise in the personal column of yours and other nearby cities newspapers.

For babygirl 9505 i doint know how to find my dad but i am just like you i doint no faer my dad is i meint him one time and i was just 4 years old and i am 13 and my mom never told me so if you woint to help me find my dad i will help you find yours