Hello Tom! ^^ Thank you for submitting your homework today. Kindly take note of the corrections that I made. Thank you! ^^

It could feel better now, when you smoke a cigarette.Howere, It is so harmful to your body.
Correct:  You could feel better when you smoke a cigarette but it is actually harmful to your body. 

your money will be waste to buy a cigarette.
Correct: Your money will be wasted in buying cigarette. 

You must stop smoking. For your whole family
Correct: You must stop smoking for your whole family.