Hi itsmebabypat,
First, good for you that you are brave enough to go to an ABDL event at all. That takes some courage and it's always awkward and scary at first.
In my experience, if you are new to the event, the best thing to do is be brave, walk up to someone and say something like, "Hello, I'm new here." That can often be a good ice breaker. You could also walk over to someone and compliment them on what they're wearing or their stuffy or whatever seems like a nice, genuine compliment. That can also open the door to conversation.
At one ABDL event I went to, I sang karaoke in front of a large group of people, mostly strangers, but because I did I hit it off with some new people and began making friends.
Or, if you do know some people at the ABDL event, ask them to introduce you to someone new that they know.
If there is an activity going on, participate in it - that can also get things moving along.
Anyway, just my two cents. It can feel awkward but if you were brave enough to go to an ABDL event, I know you can be brave enough to approach new people or participate in activities.
I wish you the best,
Tab