Hi, I've been away from the boards for some time but am back and saw your post.
Social interaction is something we all start out being awkward with. It is a learned skill that takes practice and the good news is that a convention environment such as Kumoricon is a wonderful way to begin.
Conventions are a gathering of people with a similar interest. This creates an environment where we "speak" the same language (geek speak if you will)
A way to "break the ice" and begin is to attend panels that you are interested in and take the opportunity to ask questions, chat with others attending the panel too.
If you enjoy cosplay, gatherings of characters associated with a show is a wonderful way to chat directly with people who love the story as much as you do. Similar "meet ups" offered at con are great opportunities to make new friends.
Last but not least, if you really enjoy the convention consider volunteer staffing. This gives you the opportunity to not only connect and meet fellow staffers, but interact with attendees at the convention too.
Many of us started this way making new friends and practicing social skills.
Practice makes progress and in many cases, life long friendships.
Cheers
Cat