As indicated before, in most of your classes, some form of the Socratic Dialogue will be used. One student will be asked to summarize a case, state the issue presented by it, the court's holding, and important reasoning. The professor may ask some questions designed to bring out some facts or factors the student has missed, or to test why certain facts were or were not important to the outcome. Typically, the professor will then pose one or more hypotheticals, slightly or greatly changing the facts from those in the case just summarized and ask the student to apply the reasoning and rules of the case to the new situation, to see whether the result would be the same or different -- to see whether the case would be bound by the former case or be distinguishable.
If you are not fortunate enough to be called on to discuss the case, what should you be doing? (besides heaving a sigh of relief?) Clearly, you should be listening, not only to the teacher's comments or questions, but to your classmate's answers. Compare what he/she is saying to your own possible answer. Is the student missing something? Or has the other student seen something you did not? Quite often, the teacher will not say whether the student is correct or not. It is the discussion, the argument, the reasoning, that is important, and not necessarily the "correct" outcome. So, much of the teaching going on will actually be done by your classmates. It is important to listen to them.
How would you answer the hypothetical? Ordinarily, the teacher will want to continue questioning one student for a while, but eventually may ask the entire class to participate. Wait for professor to indicate that she/he is seeking further opinions. Then, and only then, raise your hand. Don't interfere before. Surely do not shout out answers, but wait to be recognized by the teacher before speaking. Volunteer a lot. It is good to get the experience of articulating your views, even if they are then shot down by the teacher or another student. On the other hand, don't monopolize the discussion; let others have their chances too.
There may be times you will say something really stupid, and people will laugh. But don't be upset or embarrassed. You can be sure that probably others in the class had the same or similar idea. And sometimes, it will turn out that the question is not really stupid, even if it so appears at first blush. The professor may see that you had the germ of a very good idea, but just didn't articulate it well enough, or didn't know some information that would have made it sound lots more reasonable.
Take notes. But be judicious. Do not try to copy down everything the professor is saying, or your classmates' responses. The discussion is more important, and taking part in it, either actually or mentally, by listening and thinking, will serve you better than trying to write everything down. Law school classes are not usually like undergraduate courses. There won't necessarily be a "right" answer. The questions being asked may be important enough to write down. The hypotheticals, too. But it is better to be participating than obsessed with trying to take things down. Copying everything prevents the thinking you should be doing, which is much more important. Some students try to take down everything being said, but nothing passes through into their brains. Try writing key words rather than detailed sentences. You can fill in the gaps after class, and it will be more meaningful and serve as a quick review.