Igerstein,
If you have that much cash to devote to a Z you will easily beat up on a 944.
The first thing you should do is find a relatively rust free car.
Try not to spend any more than 2K on a running car.
Find a 70 to 73 car as these are lighter, and depending on the emissions laws in your area tend to be easier to smog after mods.
Then get a couple of books to read, and start taking the car apart.
Just dig in.
You'll learn more by doing this than any other way.
The Z is a relatively simple car, good to learn on.
I started my mods with new bushings, big brakes, coilovers and wheels and tires.
Then comfy seats and..............................
And SEARCH if you have any questions.
Mike.