Hai,
As you are in Teen age group 18 years.
hormonal changes will also be the reason for your pimples.
Follow the below advise to have a healthy skin.
Take 4- 5 liters of water every day.
wash your face twice or thrice day. Depends on outside work.use
aloe Vera face wash .
use olive oil externally in your face once in a week.gentle face
massage will give you skin glow by enriching blood flow.
turmeric powered application every day during bath will keep your skin away from infection.
avoid junk foods fried items,
stress.
have a sound sleep.
take more leaf vegetables and fruits.
apply herbal(tumeric,
aloevera,saffron etc) based face cream for protection from pollution and sunlight.
thank you
hope i answered your query.