Can a person be perfect? The answer is no. Everyone has his own
advantages and disadvantages. So, from my point of view, there’s
something that teachers can learn from students.
Asking a question to start with is a dangerous tactic with your reader. Will your reader have the same answer as you? Maybe not! In this specific case, there is not a lot gained from the question.
Don’t start too far from the topic. Make a general statement, in this case, about teaching and learning and then get to your point.
“my point of view” is clear as you wrote it and signed it.
There is no doubt that the relationship between teachers and students are [is] teaching and studying. However, in some situation [s], teachers also can [also] learn a lot from students in some aspects: general knowledge, fresh things [ideas], and attitude for [towards] life.
This introduction is definitely stronger as it starts much closer to the actual topic. Remember that the reader has already read your title, so is ready, generally, to read on your chosen topic. Use of a contrast transition is a good way to bring the focus closer. In this case, the writer has given the “list of three” approach.
Sometimes, people think the best things in life are free. I have three reasons which make me to [omit-to] disagree with that [this] statement. These three reason[s] are: [colons cannot follow “to be”; instead, use a comma or nothing] [the] value of things, time, and satisfaction.
This introduction is very similar to the previous one. It is clear enough, though the “reasons” are a bit difficult to guess exactly.