I found my dad in New Plymouth NZ should I contact him?

I am 14 years old and I live in the USA with my grandmother, I recently found out that the Man who I thought was my dad was not and my actual father is from New Zealand. A friend of my mother that new both my father and mother gave me his name and address and admitted that he periodically through the years calls her to ask how I am doing. I am scared because what if he does not want me to contact him, I told my moms friend my concern and she said that she does not want to get in the middle of this and that she did way to much by giving me his address and name (she is scared she going to anger my grandmother). My grandmother however does not know I have this information and says that she will stand me behind me whatever I decide but she thinks I need to wait till I am older. I know that I need to decide something because I am getting obsessed with this to the point I cannot focus on school and I am a Straight A student. I went to his facebook page using his name and found out he is a "musician" with no kids ( except me) and not married. Should I contact him or should I wait? Should I message him through facebook or should I call him? I am only asking on yahoo because I have no where else to ask without getting bias answers..:)