Iam 19 years old have had acne since I was 15 it ranges from mild acne to few pimples but the problem is acne red marks what can treat them?

See your doctor. Problems like these can only be correctly handled by your doctor in person. He/she needs to listen to you, perform an examination and possibly run labs or other tests. That's the only way he/she can find out what's going on and what to do about it.