To obtain a doctor's license in the United States, you need a diploma recognized by them, and you have to take an exam similar to the China Medical Qualification Examination. Only by passing the exam can you qualify as a doctor in the United States. The English you speak is just a foundation. Many doctors around you didn't get a doctor's license until middle age after going out, but most of them are limited to anesthesiology and pathology. You should be prepared to suffer.

Canada, like the United States, is not clear about Australia.