How to grow teen hair long fast?

Hey! I am a 14-year-old girl whose hair is about 1-inch below my ear long. I was born bald but from about 4-8 years old, my hair was shoulder-length because it was always done in ponytails and my mom used to always do it. As time ped, my mom stopped doing it and it started to continue to get shorter and shorter, the shortest it had gotten for a while was neck-length but then I started to get split ends and my hair became damaged. Now my hair is only 1-inch below my ear and I'm a 14-year-old who doesn't know how to take care of her hair but I want it to become shoulder-length by the end of the year? I believe its possible but I just don't know how to do it. I also have good genes: My mom's mom is indian (in all of the family photos, everyone girl on my mom's side has long hair), her dad is black (never seen that side of the family). My dad's mom is black (their side has medium-length hair) and my grandma told me that his dad was white (I never met him and my dad really didn't know him but my grandma also said that they had beautiful hair when I asked; I always figured that my granddad on my dad's side was white because my dad is really light-skinned and I'm light-skinned too). Im mixed with indian, white and black. Can anyone tell me how to care for my hair to help it grow shoulder-length or even past that by the end of this year? Please help if you're good with things like this? Thank you and God Bless.! =)