Congrats on getting set up. Exciting! And well done for grabbing the opp to go, it could have been easier to say "I'll go next time".
I'd agree with Tee2072, most people are nice. The ones that are not are not good client material, so just move on.
Can you do any research on the event/people that are going? Or read up something topical about your "area"? Latest CIPD survey etc re training/professional development.
I recently went on a sales course. The trainer said always get in there first and ask what the other person does, as that then gives you a chance to tailor your intro/spiel towards what they have said and the potential needs they have mentioned.
She also said that most potential clients will need developing, so tonights isn't about securing anything concerete, other than meeting people who might be interested in your services. Sorry if that is obvious, but I always feel the need to come away from these things with loads of firm biz opps.
I always try to offer something "I'll send you a link that report" as a way to connect with them and be helpful. If I promise to do that, I tend to write it on their card, so I have a reference when I get home worse for wear!
Take notes on who wins (if that doesn't look too odd at dinner), you can follow up with an email "congrats on winning...my service blah blah".
If you are on social media make sure you make the most of going to the event - tweet or blog about it afterwards. I think being out and about makes you look successful which is more attractive than somebody who isn't busy!
Good luck, let us know how it goes.
WS