I was in my school and my classmates were smoking and they blamed it on me
This dream may suggest that you are feeling guilty or responsible for something that you did not actually do. You may feel that others are blaming you for something that is not your fault, perhaps in your waking life. Alternatively, it is possible that you have concerns about peer pressure and social influences, as indicated by the smoking in the dream. This dream could be urging you to stay true to yourself and not let others lead you down the wrong path.