On first aid class i did not put correctly bandage to another person,instructor told everyone in class about me she is going hurt person.,

Strange: Sounds like you have a very ineffectual teacher. Would talk to the course manager as that was not a helpful statement for you or anyone else.

Teacher untaught!: Sorry you had that experience. That teacher needs to be taught better practices. Students are there to learn & not to be mocked or ridiculed or held up as bad examples. Unfortunately, this is far too common a practice still! No wonder people don't seek further education! Good for you for taking a class that gives you important skills to help others. Learn the skills, grade teacher after w/ an F!