How exciting for you Missy Krissy!!
I would check your particular race details first. Most of the ones I've seen have language like "headphones are discouraged" etc. I've heard of a few banning them. The race I'm running in the fall says you're not allowed to carry a cell phone, which I don't understand at all (maybe it interferes with their chip timing?).
I think mostly they discourage it because they want you to be able to hear directions from race officials if needed. Also, if its a crowded race, you might not hear other runners talking to you - ie: passing on your left, etc.
I wore one earbud for my last race, which made me feel like I was still well aware of what was going on around me. I think if that race had gotten really hard, I would have put my 2nd earbud in for major music motivation
Also, I think it's a really great experience to hear the spectators cheering you on for the first time! Very motivating!