.....yep best of luck. Just remember that your instructor won't have put you forward for your GFT unless he thought that you were more than ready for it.
I'd say that if your examiner has c30,000 hrs then that is a good thing as he/she will put you at ease and the whole thing will turn out nice and easy.
If you can't get in the air beforehand I'd certainly recommend getting to the airfield nice and early, and getting into the aviation mindset. Also, don't forget to ask the examiner how much they weigh for the W&B.
All the best.
Cricket.