Typically, at a gathering you meet up with other cosplayers as the character of your choice (in this case it's a SMT themed gathering) and you take pics and hang out for a while. Some gatherings even have dinner/lunch with each other.
Anyways, it's okay if you're shy. I mean, I'm pretty shy in person unless I know the person (but I'm rather talkative online). But if you looking for other cosplayers/anime fans in the Vegas/Henderson area check out this group: http://www.myspace.com/aicosplay