He took turn 3 a bit too "tight" and clipped the kerb on the inside of the corner, which just flipped him over.
Only times I've ever felt close to having a big "moment" was clipping the kerbs coming into the fishhook and the corner coming onto the straight.
Moral - stay away from the kerbs !! Ripple strips on the way out of corners don't hurt, just the kerbs on the inside of some corners.
Here's the best "guide" I've seen - Lap of Wakefield Park
As mentioned above numerous times, take it easy and try to keep it "clean". I always find that my 2nd or 3rd laps are the quickest in each session. After that, I try to go faster but end up with slower times. Still can't help myself though
Depends on who's organising the day, but often they have a session at the start for "newcomers" to learn the track. If you can grab an experienced driver, stick them in the passenger seat to show you the correct lines in this initial session.
My last bit of advice is to try and get your seatbelt "locked" to hold you in nice and tight. Hard to describe, and I haven't been in an R32 to see how it would work in one, but try pushing yourself back hard into the seat, then pull sharply on the seatbelt to get it to "lock" and hold you in the seat. Its much easier to drive without having to worry about sliding around in the seat.