Hi..
Welcome to HEALTHCARE MAGIC..
As per your question acne can occur due to a number of reasons like hormonal changes, oily skin, bacterial infection, Inflammation etc..
You should wash your face using facewash that contains
salicylic acid..
Apply a combination of ointments containing
Benzoyl Peroxide and antibiotic like
Clindamycin..
Azelaic acid creams are also helpful.
Exfoliate your skin twice a week gently using a mild facewash scrub..
Cold compresses over pimples help in reducing inflammation and shrinkage..
If you do not see improvement in one month
consult a Dermatologist and get evaluated and he can advise you
Oral antibiotics like Clindamycin or Muricoprin.
Retinols can also be advised..
Avoid oily and junk foods..
Take homemade nutritious diet..
Drink plenty of water..
Avoid sun and dust exposure..
Hope this information helps..