Anecdotes are always a good idea. They help the audience focus on a real situation and real people (or animals). Just make sure your anecdotes are verifiable and believable.
Since your topic is "Beating the Odds," it would be engaging if you managed to actually include some odds in your talk. That might be hard to find, but it sure would work nicely.
Your topic is very, very broad. You want to narrow it down some. Think of a specific situation in which beating the odds would be an interesting thing to talk about, such as overcoming physical disabilities, etc.