Book two lessons every week, if you can; with any luck you'll fly one of them. The other being cancelled because the plane broke, or the field is water-logged, or the instructor is ill, or the weather is inclement, or whatever.
As for the headset: at most places it is considered a part of the plane, therefore no need to worry as long as you fly a club/school plane. Even when you buy one, there's a fair chance a couple of headsets will be included.