This is a very complicated question because it involves a whole course in introductory psychology plus the application of the science of psychology to human nature, including no doubt your own human nature. Since no one else has answered this question, I will try my best to help. I believe the professor is mainly concerned with how the students will evaluate the course itself. In other words, what have they gotten out of the course? I suggest you look up the prospectus for the course in the college catalog in order to see what the professor was trying to teach. Here is an excerpt from a college catalog as an example:
This course provides an introduction to the basic concepts that form the foundation of the field of psychology.
Topics to be discussed include the following:
• The history of psychology
• Research methods in psychology
• Biological bases of behavior
• Sensation and perception
• Psychological disorders
• Treatment of psychological disorders
• Social psychology
You can't be expected to cover all these topics in a two-page essay. So you should pick just two or three of the topics that made the strongest impression on you--things that are of value to you which you didn't know before. I assume that Psych 101 courses are all pretty much alike. They are an introduction to the science of psychology. You should probably emphasize how the course has made you realize that there are many different ways of measuring, classifying, and understanding other people. Also that there are many different types of people. If you only focused on one of the topics, such as intelligence testing, it would probably be sufficient. The best thing you can do to is to tell what you found most interesting and why. You can either talk about how the course has helped you understand yourself better or how it has helped you understand other people better. That is undoubtedly what the professor is looking for and why he gave this particular assignment. He wants an evaluation of his course so that he can improve it. You can help him. No doubt you should say something about the scientific method as used in psychology, since this is an introduction to the whole science of psychology.
You might begin by reading about Psychology 101 in your own college catalog.