Spend time with her now, obviously and make some memories. But later on in life, those video's will become important. She may be too young to appreciate them now, or even in a few years, but as time goes on and her memories fade, they will take on a new importance. What you looked like, how you sounded. Being able to show those to her husband or kids will mean a lot.
When it comes to topics, don't focus on trying to impart "life lessons." Tell her about your life. The good, the bad and the ugly. The time you lost your job. The first/last fight you got into as a child. A fun birthday. The weirdest job you ever had. The girl you had a crush on that never knew you existed. Your first girlfriend. Your first breakup. Things that will help her know you. Those will impart the life lessons.
And the one piece of advice I wish I had listened to, "If you go to college, don't skip class."