You are responsible for everything which occurs in every lecture. The course will go most smoothly for you if you commit yourself now to the following habits: (i) Decide that you will attend every lecture and every recitation unless something absolutely unavoidable happens. (ii) Later on the same day of a lecture, take a few minutes to review what we covered, to identify quickly any points on which you are confused. Seek immediate assistance through the professor or TA or one of your chums in the class. (iii) Recognize that the exams will cover concepts emphasized in lecture; the emphasis given in your text to particular topics may be somewhat different. View the lecture as your primary source and the text as a supplementary resource. (iv) Spread your work on assignments over a week, rather than working on the problems all in one day. (v) Always pause for a moment after working a problem, not so much to check accuracy, but to look over your work in search of ways to simpify what you did, or argue differently, or ask if the method you used is applicable in more general contexts than the one from the problem you just did.
So are you ready? Let's have a great course!