Am I just damaging my heart?

I'm 15 years old 6 ft 1 in (185 cm) and 200 lbs (90 kg) which translates into being 20 lbs overweight.I have read somewhere that exersising while being overweight increases your stamina by working out the heart is it true or I'm just damaging my heart? I'm asking this because I plan on losing some weight for a boost in my appearance( I'm a boy after all) and in my basketball abilities. If I don't damage my heart by playing basketball in my current condition thought I will lose the weight later(when I'm an adult) since I will get even better at basketball and basketball>girls(considering that they would only be interested in my appearance). If it is a health issue now I'll ignore everything else and lose weight immediatly(1 lbs per day tops).