My son who's 2 years old has this sores like blisters,on his face and i have tried cold sore creams and antibiotics but they won't go away?

Needs exam: Proper treatment of such a rash will require a proper diagnosis. It may or may not be an infection the germs of which often hide in the nasal passages, or some other agent. That can be confirmed by exam & possibly lab testing for the germ.

Blisters: Could be impetigo which requires prescription medication so get him examined soon