Don't be so nervous about it. He's already going out with you, it's no longer your job to make him like you, he already does. Just be yourself, and see how things go. What more can a partner expect from you then to be yourself? You shouldn't feel like you have to be perfect. Besides, who would go out with someone if they were perfect? Sounds boring to me. It's imperfections that attract me to a girl. =)

And also, I agree with missguided.rose. Laughter is the ultimate cure for awkwardness and also helps bring two closer.