How do i get started

Hi, I'm a thin 17 year old kid who wants to start working out but I have no idea where to start.
I have seen so many programs that tell me I can get into the best shape possible.
But, They cost way to much then I can afford.
I've talked with a few friends they suggest,
That I wait still I'm older because my body is still growing;
Some say I would need to know everything that my body can and can not handle weight wise
The right weights I should start with, *my body size*;
The perfect eating habits. for my *size*
I don't know where to start can someone direct me in the right directions
Thanks