come on guys, if i could do it anyone can! i was the scaredy-est person on the track at silverstone (my first one) and was last left on the track at the end of the day - the rain started and everyone else went in, but i didnt want to stop!
go in the novices, take your time, be aware that the first couple of sessions will feel a bit weird and don't push it too hard.
by lunch time you won't want to stop, you'll have learnt what's coming roudn the next corner and you'll be ready.....well kind of
if after the first few laps you hate it, then it doesn't matter. you've paid your £100 or whatever (fair enough a bit more for a Ron Haslam effort) for a track experience, if you find it's not for you you've still had that experience and you'll know for sure you don't like it.
bet you do like it though

i do and i'm hardly the fastest out there, but each lap i'm learning something more about my bike and something more about myself.
my main reason for loving the track is that for those 20 minutes, you really do think of NOTHING else other than you, your bike, what your tyres are doing, what your suspension is doing, what the best line is (and why you haven't taken it yet

) etc etc. I don't think about shopping, work, home, bills, nothing except staying on my bike.