Well done M8, I started late last year at the age of 35!! never too old. You will need a Tranny, DONT buy new

(I did £245) DONT buy ebay

, second hand on ebay go for £180-£200 !! Demand outstrips supply on these!
Also DONT

buy new tyres, you would be surprised how many scrubs you can blag in the paddock

When I finally take my 090's off I have 3 full sets of scrubbed supercorsas ready for the next season.
NEver listen to advice on what gear where etc at trackside, do a track day first as Zimm sugeested on the Friday and learn the track yourself. Try and stick with someone a little faster then you, you will be surprised how you can catch up/ stay with them. If you do overcook or think you aint getting round a bend, just tuck it in and go for it, you will again be surprised what you bike will do!!
Best tip of all is laminate a tick list of what you need for a weekends racing and check it off as you pack the car/van!! I know someone who forgot his Helmet

.
Oh and dont wear your trainers into pitlane for the warm up lap like I did at Oulton

(ask Zimm) Had to start at the back of the grid after putting on appropriate footwear.
Finally best advice is don't worry about falling off or coming last and enjoy yourself.