How to make my hair grow long.?

Hi My Name is Jessy.Im African American N 13Yrs Old.I Want...Well Me N My Mom Want To Know How I Can Make My Hair Grow Longer.I Don't Want Anything To Make My Hair Grow Thick (Ive Broke Enough Combs) Loll.Is There Things I Should Get At A Beauty Supply Store? Someone Said By Flat Ironing My Hair Every 2 Weeks It Would Grow..Buht It Just Started Shedding So I Went Back To Braids.What Can I Do??