How to get rid of moobs and tummy fat?

I am not overweight but have a layer of fat over my tummy and chest.my are puffy and my chest looks like a .Please advise any method to build muscles and get rid of tummy and chest fat.I am 15yrs old,height around 178 cm and weigh 55 kgs.I have been weight training for a month and my biceps and triceps look toned but my tummy and chest make me embarred, especially while swimming.Please advise some measures to make my chest look good.