Is there any specific material to bring?

No, come as you are and have something to write and something to write on ready.

Do I need to share my insights publicly with the group?

No. You can share what you're comfortable with, but will never be pressured into sharing what is not.

What are the benefits of self-reflection?

Self-reflection provides more clarity and focus and enables your brain to learn better from past experiences. You'll get more awareness of yourself and gain more insights into what moves you, motivates you and touches you. Lastly, you'll cultivate a stronger connection to purpose and creativity.