To treat acne and its related dark spots, wash your face twice daily using a mild soap; apply an oil-free moisturizer and avoid pricking or scratching at any pimples. Over-the-counter products containing benzoyl peroxide or salicylic acid would be effective too if used consistently for about twelve weeks. If none of these measures work for you, you can see a dermatologist who will give you more instructions based on your specific needs.