I think it really depends on your priority of finishing vs. 8 min. pace.  If you're training properly, stay healthy, and well rested by race day, I think you can probably do both.  I would recommend starting a little slower than 8 min./mile just to see how it feels.  Chances are, with the excitement of the race, you'll have to hold yourself back.  After a few miles, if you find that you're pretty comfortable and can go faster, then bump it up a little.  If you're struggling, then slow down a little.  You don't have to be perfectly consistent on pace.  Just keep asking yourself, do I feel like I can maintain this for X miles.  Even if you average just a little over 8 min/mile through most of the race, you probably will have some adrenaline kicking in near the end to help you finish strong and make your goal.

In my opinion it's a lot easier to crank it up a little in the second half if all cylinders are firing well and the weather and the stars are aligning nicley.  If you feel like keeping it conservative, that's fine too.  If you burn yourself out in the first half, it's hard to enjoy anything in the second half.  Hey!  It's your first race.  Set yourself a beatable goal for your next one and enjoy the whole experience.

On the other side of things, it is way too easy to over think the whole thing,  Relax as best you can and just plan to have a great run and not to kill any dragons.