Acne is due to an overactivity and plugging of the oil glands.The main cause of acne is increased levels of hormones during adolescence. The white dot in the middle is due to white heads.
Acne usually lasts until age 20 or even 25. It is rare for acne to leave any scars unless picked.
Just keep the face clean by washing with a mild soap atleast twice a day.Pat it dry and do not rub it.Avoid picking or pressing the acne.One can also use Benzoyl peroxide 5% lotion or gel or clindamycin lotion once at bedtime. An amount of lotion the size of a pea should be enough to cover most of your face. If your skin becomes red or peels, you are using too much of the medicine or applying it too often.If the condition does not improve then oral antibiotics may be needed.
Hope it helps.Take care and pls do keep us posted if you have any additional queries.