Don't stress, you will feel overwhelmed at first but as you gain experience it will all come together. Moving between exercises is a common teaching technique to keep students interested as well as encourage you to think on your feet an recall previously taught information.
6-7 hour is early days, you still have lots to learn, enjoy the experience.
The PPL syllabus is not that massive when you break it all down but some areas are very important e.g. stall recovery, unusual attitudes, slow flight, this might be why they are being introduced early as you will have a better understanding of why flying straight and level is important, especially as you proceed to nav exercises where you will be multi tasking to a pretty high level i.e. aviate, navigate, communicate.
Don't be shy either, be open with your instructor, you will learn quicker and have a better understanding of flying, it's not about learning as fast as you can, it's about learning to become a good pilot, take my word on that.
Are you doing an intensive course? Just PPL? Or more?