The first lesson I would want to let my private pilot student know what I expect them to do and what they can expect me to do. Things I would expect the student to do are: be ready for their lesson at the time we are scheduled to meet that way we can make the most of that period of instruction and not waste instructional time waiting for the student to get ready, give me some warning they are going to cancel and not waiting until the last second, and study material outside of the instructional time and to come up with questions on their own for me about things that peaked their interest.
Things the student can expect from me are: returning phone calls or emails within 24hrs of receiving them, making time to meet outside of our regular meeting blocks if the student desires, making arrangements with another CFI if I will be out of town, and will give the student a suitable heads up if I cannot meet and will reschedule promptly. These are the things I would cover with a student on a first lesson making these things clear will help keep the environment professional and responsive. I would also ask the student if there are other things they think should be in here that are not.