I would definitely try to avoid beginning your autobiography as if it were an encyclopedic entry. (Example: "I was born on January 1, 1995 in New York, New York to the parents of John and Mary Smith.") Nothing could be more boring or less inventive. I would probably try to begin your autobiography with a specific event that occurred during your life--preferably one of high interest that will catch the reader's attention and continue to hold it. You should eventually give a historical background about you and your family, but I would try to position it after your introductory opening.