if your a teen, with good response to training, a good build ( small joints, big muscle bellys) dont fuck about playing it safe, hit it realy hard...
train from 16 to 19 natty, learn your form, get your poundages respectable, get used to dieting... then hit the gear properly, stay on all year round and try your luck on the stage, you can realy change your body at the point of your life.