How do I change myself for the better?

I have an extremely hard time being social. Whenever I am at a party (that does not envolve my close friends) I tend to sit by myself and bide my time. When people ask me something I don't know how to respond to it other than small one liners. I don't feel I have anything to say and find myself being fed up for even going to these parties. How can I change? I would like to become more social