Listen to your instructor, do what he tells you and buy him beer. Mostly the last of these
Best advice: work hard but enjoy it. Straight-forward path to a successful PPL, but not always easy to follow. The course is unlikely to demand anything of which you are not capable, but it is by no means easy.
Don't get down if your instructor tells you what you are doing wrong or could be doing better all the time. We all do that. I, and many others would also be praising you when you did it well / better than last time, though some are curmudgeonly sods and won't do this. If you are not happy, talk to the CFI about a change of instructor (even if he is the CFI, he shouldn't be offended as instructor/student incompatibility is an accepted problem). If it is your fault (you wil know, if you are honest) then work harder!