Don't panic about speaking to academics - I am also quite shy and found that when I went to my first conference last year, the academics tended to be keen to talk, so all I had to do was be willing to listen! Try to seek out other PhD students, as they tend to stick together and not talk about work all the time. I'm sure that looking back, you'll be glad that you went along, and at least at your next conference, you'll see some familiar faces so it won't be nearly as nerve-wracking!