Networking events can be intimidating and if you're not comfortable at the start then that makes it harder. Why not try something like this: make a decision that you will have a conversation with just ONE person. Just one. Breaking it down into smaller steps makes it less overwhelming and easier to manage.
When you get there, look for someone you'd like to get to know better. Then find an opportunity to connect with that person. Remember that everyone is there for the same reason, to network with others.
Networking is like anything else, the more you do it, the better you get.
Maybe you could seek out the organizer of the event and ask them for guidance. I'm sure they'd be willing to give you some tips. Or, maybe you could volunteer to help them at the reception area or something like that.
Just some ideas.