How to improve sprint time?

I am 15 years old. I ran track for the first time yesterday. I did average. I would like to know how to improve my sprint times, what drills to do, and general tips on track, I want to achieve personal bests not win meets, I am a former 1500m runner and my personal best was 4:30. I ran a 14 second 100m yesterday but bear in mind it was 33 degrees, I never trained before and I was wearing the wrong attire to run, furthermore I was dehydrated so I aim to get 12 seconds within the next two months by improving my technique. Duces