try concentrating on just one person in the audience to whom you feel comfortable singing to… but make sure that that person will be sitting in the center within the first three rows, because with the bright lights thats pretty much all you’ll be able to see (which might be a good thing for the nervs!)
also – try not to worry so much, people are not there to laugh at you, only to chear you on! even if chas veshalom you do crack up, i promise they wont laugh! 🙂
i hope this helps! good luck!!!! 😀