Hi,
One of the first mistakes new dancers make is to assume that everyone is watching them. No one is watching you. Honestly, everyone watches dancers that are a level above. Also, no one expects you to be perfect. You will miss leads and make mistakes but we all do. Just keep dancing with a smile on your face and you'll have fun. I once was dancing with a man and having a terrible time staying on beat and getting the steps right. I thought it was a disaster but when we were done he said to me, "I like dancing with you, you're always smiling and laughing when you dance."