Set some goals for your car. Have a vision of what you want it to be .. then you work towards that one step at a time... If your looking for more power or better handling or appearance....
The first steps on the power side of things are the cold air intake and throttle body porting and headers.. the factory exhaust flows decent enough.. then you have a cam and head work and intake work or a power adder
basic speel is this: The engine is an airpump.. more air in more air out more power made.. sometimes its just a matter of removing restrictions
suspension.. putting what you have down more efficiently will allow you to use more of the power you already have
Appearance is obvious...LOL but still if you want that special look you need to build it in steps as well.. wheels, tinting, lowering, highlights