It worries me a lot to hear that you have got into the habit of smoking.
Smoking does great harm to people, and it’s foolish of you to think that teenagers like you will be free from the harm. Lung cancer is one of the most serious illnesses smoking will cause. Smoking is also a waste of money. Besides, careless smoking may cause fires.
Therefore, I strongly recommend that you give up smoking as soon as possible. The earlier you start, the earlier you will get out of the habit. Make non-smoking friends and get support from your parents and teachers if necessary. I hope you’ll be a non-smoker soon.