For one event, it’s not that much depending on the track. A one day event at Monticello (like with Mo-Hud SCCA in September) is around $250. That’s for their full course which is 3.5mi long. The only things you need are a helmet, pants, and a long sleeve shirt. I’d highly recommend a set of track pads, like Carbotech XP8’s, as a street pad will fade way too fast. On my first track day ever, I cooked a set of Hawk Performance Ceramics. It’s not hard to do though.
You have very good brake calipers and rotors stock, so a set of pads would get you a pretty damn good brake system.
There was a white Evo there in my run group as well. Guy was pretty fast, or faster than me at least lol.