I need help i want to met my dad but i dn't no much bout him?

ok well im14 yr. im not sure win but like win i was 2 my real dad left my mom n me n i hav always lived with my mom now i hav a step dad hiz been there 4 me since i was like 7 yr.old but itz not da same i want 2 find him bout all i noe bout him iz hiz name n last name how can i find him cuz i hav seen wed sites 4 lookin 4 ppl but u hav 2 pay n i dn't hav money could anyone give me some advice bout wat 2 do plz well thanxz =]