M an 18 year old girl with weight 120 lbs. m 5'4" but my waist is too slim. i want to put on some lbs on my waist. kindly help me the way u can?

Slim waist: Any weight loss or gain goals need to be discussed w/your doc for safety and effectiveness reasons. You need to make sure there is no medical reason for your concern. After that you can see a nutritionist and/or a personal trainer at a gym. Above all, remember that the most attractive people are those who are neat, clean, and treat others they way they would like to be treated. Peace & health.