Applied Neuroscience Strategist, K-Selected Biohacker, Tantric husband, Promethean peaceful parent, Adventuring philosopher, Raconteur & Author. He spent +14 years researching the intersection of human performance enhancement and advanced personal growth in his obsessive quest to find real-life "NZT-48."
Attending public events and pushing yourself outside of your comfort zone is one of the most direct ways to crush social anxiety (especially if you're on social smart drugs!)
I've got a few things for you to try...
The Elbow Tap
You won't always have the opportunity to approach someone from the front, practice approaching people from the side (or even back) by tapping their lower elbow, it's a nonintrusive way to get someone's attention that works quite well actually.
Find a Social Foundation
Since you are likely solo at this event, you'll find yourself alone from time to time. You want to establish a foundational person or group that's receptive to you whom you can return. This is maybe someone you know from elsewhere, a friendly group of guys, or the event host themselves.
Number Closing
Anyone whom you talk to for more than 10 minutes, get their number, Facebook, or contact details. Even if you don't intend to follow up with this person, get their number arbitrarily. Just get in the habit of asking, you'll be surprised how many say yes.