Welcome Paul,
Expect nerves, tension, worries, bowel problems! And that's just the rest of the field never mind you!
Seriously, you'll enjoy it as long as you don't set yourself too high a target. Don't go off too fast and make sure you take on liquid to keep hydrated. You will be nervous but that's normal...I still get nervous and I've done many races.
Give yourself plenty of time to get to the venue...that way you'll find a place to park and you'll be ablle to take in the atmosphere as it builds.
Oh and by the way....Dave's right!