The first thing is don't pop your pimples, let them fade naturally. Always wear some form of UV protection and keep your skin clean and moisturized.
Acne scars do not go away entirely on their own. Depressed acne scars often become more noticeable with age as skin loses collagen. However, there are a variety of treatments that can make acne scars less noticeable. Post-inflammatory hyperpigmentation may lighten on its own within several months.
Acne scars range in appearance from shallow, mottled depressions, sometimes called rolling scars, to deep and narrow depressions.