Something else that you may encounter when going from a 152 to a 172 is a vastly upgraded avionics panel. Most 152s I've seen still have one old mechanical radio, while lots of 172 have been built later, or upgraded later, to include two relatively modern radios, audio panel, intercom, various nav radios, maybe a GPS, you name it.
Before you take your first flight, it might be worth just sitting in the aircraft for an hour or two, preferably with ground power connected, to find out what the different boxes do, and how you make the proper box do what you want it to do.