It's my first car, what should I expect?

[DISI7]

My parents just bought me a used 2007 CX-7 with the MZR 2.3 DISI Turbo engine or more simply put the 2.3L turbo inline 4. The car had 54,649 miles on it and now currently has 54,942. A lot of people on edmunds.com totally bad mouthed the car which to me is disconcerting. Most complained about the timing chain the vvt valve and the compressor. On the other hand I have heard some people have 80+K miles have not had a single problem. Right now both heater and a/c are rockin' (knock on wood). How ever some times something kicks on and makes a slight and constant squeak like sound and the goes away ( I fear that it may be the timing chain stretching). Then after I kill the engine it sounds like the fan keeps going and when it stops it squeaks twice. Is this normal for the car? Are the majority of these cars reliable or should I be worried?

 

[Seanfig03]

I'm on my 2nd one, due simply to the fact I traded my first one in for a cx5, hated how slow it was, missed the zoom zoom. The only problem I ever had between the two was a bad a/c compressor on the first was, but it was fixed under warranty. That is all