Hello.

I'm at 5'9", 50kg, 16 years old.

I wish to bulk up to 65kg by Mid 2018.

I'm not sure of my body fat percentage yet, I think it's at 20% looking at the image I see online.

What should someone such as myself do to gain weight yet have a low bodyfat? According to BMI calculators, 68kg is the optimal for me however I hear that normal on the high end BMI is actually overweight.

Do I bulk first and then workout (converting the fat to muscles)? Or continuing lifting and eating?

Thanks!