I want to learn, three languages, which one to learn first?

O.K. I really wnat to learn French ,and Japanese ,but I know how handy Spanish is and how many people know it.Also people say to learn spanish before other languages if your english. Why? Wouldn't that just make it longer until I learn French and Japanese. The languages I really want to learn. I want to learn french because I want to volunteer in French speaking countries (Africa).I am part Japanese and I hear my grandma speaking it all the time, unfortunately she hates me( really) so she never taught me, but I have picked up and the pronunciation comes easily to me, where as French is pretty differant.Anyways I want to learn French first but if learning spanish first would help than I'll do it.I want to know all three anyways, but French and Japanese take priority.Please ,your professional advice or personal experience is welcome.Sorry for all the I and ME stuff ,but I want to learn to help people, and go to differant worlds.