Hello, have more of fruits and vegetables, drink lot of water , avoid junk ,oily food items ,have food like chapatis, avoid curd ,ghee, ice creams , meat .Exercise daily in morning , sleep well ,avoid worries, Pimples at this age could be due to harmonal variation its quiet common ,wash face twice daily avoid dust and pollution, don't puncture pimples it turns black, let it fade on its own , don't apply steroids without prescription