I would hold off on any mods. Maybe just get some Azenis and drive those for a year.

DOT R tires like Fuji says can't really hide your mistakes and make you a worse driver in the long run. You can also destroy a set of expensive ($400-800) DOT R tires at your first autocross if you don't know what you are doing.

You will learn alot quicker on how to be fast and brake harder on street tires. Street tires will squeal and skitter which is what you need as a novice to learn the limits of your car without worrying about killing a nice set of R tires.

Worry about DOT R tires and suspension work til you get at least 10-15 events under your belt. Get some driving schools in first this year or the beginning of next year.