I'm frigid but I dont want to be?

I am going out with this boy but I haven't done anything with him apart from hug and hold hands a few times. I can tell he wants to kiss me or whatever but I'm nervous. Apart from truth or dare and spin the bottle I have never had a first kiss with a proper boyfriend. I'm worried I will mess up or laugh in his face or... You get the idea. I am also worried about the fact I have train track braces. I don't want to be frigid but I really am. What shall I do? Please help! I don't want him to get bored of me!!