Order a copy of the Pilot's Operating Handbook from Yingling Aero, if you really want to get ahead of the game.
Then actually READ it

.
For example, there is a specific starting procedure which verifies several things regarding the electric backup pump. There are three speeds for that pump, and if you don't want to be finding a place to land off airport, it's a good idea to verify that all three speeds actually work prior to flight. One of those speeds is controlled by a mechanical connection to the throttle.
That's just one example. This is NOT just a big 172. Bigger, more complex engine, more systems, yada, yada, yada.....
Learn everything you can about the airplane BEFORE you start trying to work it, and you'll be more comfortable and more proficient.
What model is it, by the way? Lots of variations in fuel tanks, etc.
Great airplane, period. We switched to a big engine 206 from a 185 (it wasn't my choice) and I never looked back. That 206 was a workhorse.
Heavy controls is probably the first thing most folks notice. It's designed for stability, which is why.
MTV