TBH, I wouldn't advise it. I started smoking at 11 and soon afterwards, was convinced I came from the planet pluto and could speak to dead people (I'm being absolutely serious here). Even the mother of the girl who supplied it to us thought I was nuts....and I was. I've suffered with mental health problems ever since, yet it was only in my 30's that I was able to connect the start of my cannabis use to my psychotic delusions.
I'm ok now- I manage with a personality disorder and I've narrowly avoided schizophrenia (I have a schizoid-avoidant personality disorder), yet it doesn't mean I won't develop it later on in life.
The thing with cannabis is that it's like russian roulette; you could smoke & be absolutely fine, but there's also a chance that it could (a) ruin your memory (b) make you paranoid (c)spark off psycholotic delusions- and these may last for hours, days or weeks afterwards.
Your brain is still growing & developing- let it do that. If you choose to experiment as a functioning adult, then that's your perogative. But as a child- a growing, developing person with a huge amount of potential in life- you are best sticking to experimenting with sugar.
Take it from someone who wishes she'd never taken her first puff.
Good luck & I hope you make the right decission.