The first day of class is your opportunity to present your vision of the class to prospective students. It is helpful if you can introduce yourself as a scholar and educator and provide insight into how you will teach the class and what you will expect them to contribute to the learning process.
Consider that several of your students may be “shopping” for a schedule the first week of classes. They may be looking for a class that will fill a particular time slot, include a particular learning environment (i.e. lab-based or lecture style), or a class with a certain workload to balance the demands of their other courses and extra-curricular responsibilities. Thus, students will appreciate a clear roadmap of what you will require of them over the course of the semester. You may also want to model, as specifically as possible, the classroom environment you intend to foster during the class. For example, if they will spend a good deal of time doing group work over the course of the semester, you may want to break them into groups the first day.