While it's impossible to prepare for every possibility, there's much you can do to prevent misunderstandings in the future. Before that first lesson and before you say, "You're Hired" take the time to talk about a few things. You'll be glad you did.
Of course you'll want to talk about the location, time, and frequency of the lessons. But here are a few very important topics that often get overlooked.
Rate: Yes, the tutor probably has a listed rate (and if not, you might be able to negotiate the rate). Be sure to ask about discounts. Many tutors will offer discounts for things such as: Military, pre-payment, lessons scheduled during off-peak hours, and multiple hours at once. Even if the discounts aren't advertised, it can't hurt to ask!
Cancellation Policy: What happens if you need to cancel a scheduled lesson? How much advance notice is required? If you are charged for a lesson, can that charge be applied to future lessons? What happens if the tutor cancels a scheduled lesson? Does the tutor respond with a free lesson?
Payment Policy: What methods of payment are accepted? You might be surprised. More tutors are now accepting methods of payment besides cash. Some even offer PayPal. If checks are accepted, what is the policy if a check bounces? When is payment accepted? Most tutors expect to be paid at the time of the lesson. However, if you schedule frequent lessons, you might be able to arrange to make payments less often. I have many students that pay once weekly.