How to get better at 3 kilometer runs?

I am 13 and at 1500 metres I got approximately 5:00 so at 3000m I would probably get a little more than ten minutes. I am a city finalist and I have a race after the summer so i need a good training schedule to get 9:00 on 3000m. If 9:00 is unachievable then one that brings me to 9:30 is acceptable. I am not a very fast sprinter so maybe sprinting could be important.