On M-1 student visa, you may:
Note: Once you are six months into the program of studies, you are prohibited from changing your course of study except under truly exceptional circumstances.
No, you may not work on M-1 visa. However, you may apply for practical training after you complete your studies. If approved, you will be allowed to have one month of practical training for every four months of study you have completed. You will be limited to six months total practical training time.