How do you make your hair grow faster?

hey i got my hair cut a little too short. its like sitting right on my shoulders. i want it longer so badly!!! i dont want extentions or anything since i am only 12 but i want i like 2 inches longer. i dont wanna like mix ingredients like honey and avacado oil or anything. but is there a way to brush it so it will grow longer, a type of shampoo, when i should take showers (everyday, every other day, ect...) i got it cut like a month ago and i am gonna get a trim in like another month in a half or so. please help....ahhhhh!