Hello there,
What is your height? The weight of a person depends on his height. At your age you should indulge in outdoor activities and eat healthy food. Avoid junk and fast food. It is important to rule out conditions like hypothyroidism which can lead to excessive weight gain. A person wanting to lose weight should do so in a scientific way for long term benefits. A healthy diet and regular exercise or incorporating yoga into your daily regime can help to lose weight. I suggest you to eat frequent small meals and eat more of green leafy vegetables, fruits and protein and less of fats, butter and potato etc. Drink lots of water and consume fruits rich in vitamin C as it is a fat burner. All these will definitely help you. Do keep me posted. A calculative and disciplined approach will be helpful. Hope this helps.
Take care and regards!