Try Opei oils, they offer us member discounts. Get a good oil and some track day pads. I wouldn't consider going to a track with worn brake pads.
I would do the brake fluid, brake pads & check the disks, Check the PAS fluid, change the water and coolent and use a little "water wetter" as well. New plugs and air filter are also a given and a synthetic oil of the correct grade for your oil.
It would also help to get a decent set of tyres, you need as much tread as you can get on a track day. Eagle F1's are brilliant for the track but wear quickly (or at least they used to) or some Toyo Proxies or a road legal slick tyre.