15 Year Old Fitness Proportion?

I'm 15 and recently started dumbell training, i can see a increase in size in my arms and my Abdominals. I train everyday apart from sunday, but i was wondering wether i need to introduce cardio into my workout, because i don't want to gain any body fat. My diet isn't the best but its not the worst either, i try to keep up on proteins but do i need to go jogging in order to keep my body shape, as well as lifting weights? Thanks in advance.