A interviewer is partly interested in your acedemic knowledge and is solely interested in you. He always looks for confidence in his employees. so even if a person X does not have a very shining...
It is far better to be yourself and perhaps not win over every young man you meet than try to be something you are not impress him. Be yourself and see what happens.
Make her laugh. All of my friends a guy who has a sense of humour. We also all desperately want a guy who is mature and sees us as more than a pair of breasts. Talk to her to show your interest....