There are several ways to approach this.
You could just run the car as it sits, which is what I would do to determine that yes, this is something I would like to pursue more seriously. When you run the car you will have your complaints about the car, it has too much body roll, tires don't grip well, etc OR you may find that YOU need some more seat time. From that point you can decide financially which direction you wish to take with the car so that YOU get the most enjoyment out of the car, and it becomes more competitive as a result.
It looks silly from the experienced side if you show up with a fully prepped car and don't know how to drive it. Plus you will appreciate your changes more if you do a little at a time and adjust to it's new driving habits.