just don't worry
if you go in there feelign self-confident and happy then everybody (especially the people who haven't come with anyone either) will go "ooohhh wow she seems really nice and friendly i think she seems like somebody i could easily make conversation with"
haha
just be yourself and make small talk with the person sitting next to you by saying I like your pencil case. My name's such-and-such by the way.
that kinda thing
haha I never really had an issue with shyness but that's what I would do
be confident and don't worry!
everyone will love you
good luck and have fun
sarah xx