Hi. Greetings. Pimples do leave spots especially if inflaamtory or not treated or if we burst pimples. For marks You'll need skin lightening creams for a specified duration, and this could also be dealt with chemical peeling. Also you must use a sunscreen to prevent darkening of the spots. For scars, creams may not work, and you may need procedures like microneedling, microneedling rf, fractional lasers, prp or subscision or a combination of these depending upon type of scars. Send in your pictures if you need further assistance. Or see a dermatologist near you and discuss the same with him. Hope this helps. Warm regards.