"How do I become a more interesting person?"

Have interests beyond being interesting. Be an interested person, and be willing to share that interest with others.

I'd change the question a little. Unless this is about self image "I am an interesting person", if what you want is to have more people to be interested in you, there is an obvious strategy to that - sell yourself as best you can. Figure out your "interesting" comparative advantage, identify your target market, and sell sell sell. Advertise what you've got to sell to people who might be buyers