Firstly my friend, you need to post this question on the Body & Soul category, not adverts!
Secondly, at 14 why on earth would you want to subject yourself to all of this, you wont stop growing until you are around 21.
You could follow my course of action, at your age i was only 5`3" and was very thin, i decided to take up a Martial arts, and did so for over 10 years, achieving black belts in two forms, and obviously being really fit and healthy at the same time, i am now 42 and 6`2" but still thin, and glad of it.
The effects of BODYBUILDING vary from person to person, i did do weights for a time, but when i saw the effects from people who used to train a lot, i was taken aback, all the muscle had turned to flab and it was not pretty. Not all people suffer the same afterwards, but you should be aware.
Seriously, go to a gym, and get a professionals advise, about the pro`s and cons, and then make an informed decision, whether it be weights or martial arts or any sport, it will help and reassure you, that it is what YOU really want!