Many of these meetings are set up to allow people to talk about their stuff for a few minutes. This is a great way to "break out of your shell" and gives you invaluable skills in pitching and communicating what you are working on.
Get your confidence up to participate and talk about some coding you are doing. You might find someone who shares your interest to collaborate with.
Beware of service providers unless you are looking to meet them. Attorneys, head hunters, recruiters, and other non-developers also tend to hang around these meetings to get closer to --- you the in-demand developer!
I like hearing from recruiters - if only to get a sense of what frameworks coders are using these days.
But, attorneys, really?