Hello im Dr. Subin. At the age of 19 it is normal to have a few pimples. Avoid having oily and fried food. Use mild face wash to keep your face and hands clean. Pimples happen when the oil glands in your face produce more oil and due to some reason they are not secreted out. By keeping your face clean the pores on your skin will be open and all the excess oil will be drained out without getting blocked and causing pimples. By keeping your hands clean and not touching your face, you are helping yourself to restrain from any possible secondary bacterial infection.