You can read this book on your own. There are plenty of examples. The exercises illustrate the ideas you're supposed to master. With some effort you can get a lot out of this text.
But if you read this book just by yourself, you'll miss the discussion and exchanges in class that make the ideas come alive. Many of the exercises are designed for discussion. That's where your understanding will crystallize, and you'll find that you can begin to use the ideas and methods of critical thinking.
You'll get the most out of discussions if you've worked through the material first. Read the chapter through once, with a pencil in hand. Get an overview. Mark the passages that are unclear. You need to understand what is said—not all the deep implications of the ideas, not all the subtleties, but the basic definitions. You should have a dictionary on your desk.
Once the words make sense and you see the general picture, you need to go back through the chapter paragraph by paragraph, either clarifying each part or marking it so you can ask questions in class. Then you're ready to try the exercises.
You should try all the exercises. Many of them will be easy applications of the material you've read. Others will require more thought. And some won't make sense until you talk about them with your classmates and instructor. When you get stuck, look in the back where there are answers to many of the exercises.
By the time you get to class, you should be on the verge of mastering the material. Some discussion, some more examples, a few exercises explained, and you've got it.
That pencil in your hand is crucial. Reading shouldn't be a passive activity. You need to master this material. It's essential if you want to write well. It's essential in making good decisions in your life. If you can think critically, you can advance in your work. No matter where you start in your career, whether flipping hamburgers or behind a desk, when you show your employer that you are not only responsible but can think well, can foresee consequences of what you and others do and say, you will go far. As much as the knowledge of this or that discipline, the ability to reason and communicate will speed you on your way. Those skills are what we hope to teach you here.