I have to do a presentation about John Irving, or about his books or life etc. I'd like to know what other ways are there to present to a class, because I can't present just orally to the class due anxiety and I basically forget what I try to tell the class.
You are not alone in experiencing this kind of anxiety. Students, businesspeople, and even actors have this problem. The trick is how to address it.
I do not think that you will be able to get away completely from speaking in front of your class, and the key to being able to do that at all is preparation. If you have a good outline of the points you will cover and you practice what you have to say, either alone or with a friend or family member, that will go a long way to easing your anxiety. Organization and preparation can get anyone through because you will have "imprinted" what you want to say in your brain. Trust me - this really helps.
Now, to limit the time during which you feel anxious and self-conscious, there are some ways to add to your presentation that will help. One strategy is to prepare some handouts for your class. This will take some of the focus off you and onto the materials you handout. Another strategy is to ask your audience questions. This takes some of the focus off you, and it also has the benefit of allowing you to feel more like you are just having a conversation with your audience. When I have had to do oral arguments in front of the Supreme Court of my state, I have told myself repeatedly beforehand that I am just going to have a conversation with the judges. You would be amazed at how much that helps.
I do think John Irving is a great pick for a presentation. He is an underrated author, and one of my personal favorites. One idea that you might focus on is how many different kinds of novels he has written. Each one is its own little world. Another aspect that you might consider focusing on is to what degree he has incorporated parts of his own life and his own beliefs into his novels. I do believe that he wrestled in college, for example, and so does Garp.