Everyone says toothpaste works for pimples but does it heal acne marks?

Toothpaste do teeth. Leave toothpaste for your teeth. There are many things your dermatologist can recommend for acne and pimples.
No. Scaring after acne can not be eliminated or diminished by toothpaste.
NO. You will need to see a dermatologist to help you with acne scarring. Probably need to have a combination of laser and fillers.