What's a good first line in a song to write to a 12-year-old girl?

I mentioned earlier that I have a crush named Lindsey with Amazing brown eyes, with flowing dark brown hair and her smile is great. I'm writing a song to sing to her on her birthday. But I can't come up with the first line. Can someone help me? And what notes should the words be on? I'm not a very good songwriter so I need help plus this is my first song. Thanks!