Try and treat it like a normal driving lesson, just with a different instructor, that helped calm me down for mine. Oh and don't over think it! Good luck!
Just drive, it's no different to lessons to be honest with you. If anything it was easier than lessons as you don't have anyone in your ear the whole time so you can concentrate a little better, you'll be fine
Right near the end of the test there was a bit for car to wait in at the traffic lights and I crept slightly forward and went into the bicycle part on the road markings. I couldn't reverse or anything to rectify the fault so I knew I had blown it.
Unlucky. If that's the only thing you failed on you were a little unfortunate. At least that means the rest of your driving is up to standard so you should easily pass next time.