Hello! Acne is common in teenagers. You can read my health feed on practo on Top five causes of acne. Do not break them. Reduce junk in your diet. Be consistent with any  treatment you start. There are many options like peels etc for  better results. Inspite of all measures one odd pimple might just crop up but if you do not break or  touch it, it will settle without any marks or scars. Hope this helps.