pimples in teenage are common. they occur as a result of harmonal changes . once the harmones become stable ..this problem of yours will reduce by itself ... what you can do is ......Maintain good facial  hygiene ...wash your face twice  a day with suitable wash . avoid spicy and junk food keep yourself hydrated by taking adequate quantity of juices and water . see to that your digestion  is proper ...to avoid any stomach ailments , constipation etc ...as these have affect on your skin..... remedies :apply mixture of cinnamon and lime juice on the pimples and dark spots .keep till it dries and then rinse off without  using soap ..just use water . internally take manjisthadi kashaya 2 tspn with 2 tspn water twice a day 1 hour before breakfast and dinner. take triphla  churna 1 tspn  with  warm  water  at bed time ....