Congrats, the big day is upon ya (Sunday race?)
You are going to be shocked at how adrenalin will move you along. In fact, if one is not careful, one can go out "too fast". But thats not really an issue in a 5K.
I started with 5ks 4 years ago. I have run off and on all my life. Then 10ks, the 15ks, then half marathons, then marathons, 50Ks and up. (wow, that looks like an addiction problem, does it not?)
Do not let someone elses pace drive your pace. Run YOUR race. In racing there is DNF, DFL, and DNS. DNS is the worst (did not start). DNF is "did not finish", and DFL is something about being the last person to finish a race. Except for rare cases, 5Ks are speed races more suited to younger folks. Older ones (like me like the longer ones ) where a 20 something speed demon needs more than speed to finish. Do you have a Fleet Feet store in your town? Or a very running-community oriented "runner's store"?
Before I go, I want to give you a tip about something that I noted in races, especially speed races. I bet you will find folks in front of you and behind you. The ones in front, remember this, they are struggling JUST like you. The ones behind, they are having even a tougher time. Get it?
Good luck, can't wait to hear how you did.
Mike (who just ran in a 50 miler today, 4 years after staring to race)