Welcome!
You want to compare the different models and go for a test drive to see if the Z is for you.
The next thing is what plans do you have? Leaving it stock? modding for looks or track?
Those are the things you need to decide on, and from there you can ask what the best way going about it.
Start with the Nissan website if you haven't checked it out?
Nissan USA - Configurator
Use the Advance search feature for the basic questions? chance are they have already been asked