what do you think about this teacher?

The professor you have described seems totally not effective in teaching. Your class can always ask for a curriculum and schedule of topics to be discussed every meeting. It's available in the Dean's office. You can also talk your dean about this problem to solve this matter. Another thing, there is an evaluation of professors your class can make recommendations on how to choose professors for this subject.

There are many loser teachers of that kind everywhere, I advice you to change into a different teacher's classroom, or you'll have to pass that course without learning a single thing at school!

This is a very bad situation. You as a student who cares about the things you will learn from all the subjects you have enrolled or you are paying for, you need to take actions. When taking actions you ned to get hard copy proofs. First you need to make sure that your observations are not just because you don't like the teacher for some reasons. That teacher won't be there if he /she is not licensed to teach. If this is the case, dig more infos and report your concerns. Your money must be worth the things you'll learn. Education is a lifetime gain. Don't be judgmental. Ask around and but be sure your opinions are valid. Good luck. =)