Pimples and acne with dark marks are usually due to excess oil, clogged pores, and inflammation in the skin. Keep your face clean with a gentle wash, avoid touching or picking, use light non-oily products, and protect your skin from the sun to prevent marks. Maintain a healthy diet, drink enough water, and manage stress to support skin healing. If it keeps coming back or leaves marks, consult a doctor for proper treatment and to improve your skin health.