Student Exchange Programs

Okay so my parents know I want to go to Japan and my mother is willing to talk about it but my father wont! They both say it is a possibility. I want to leave when I turn 15 (or around that time) which is in like 14 months. My father barley says anything and I need to know how to get the answer so I can seriously begin to plan the trip! My father doesn’t understand that I need to fill out and application and such MONTHS in advance. How can I tell him this so I can plan?