Lesson 4 is about chapter 2 and 3.
Chapter 2 and 3 emphasis two roads to freedom. Jnana yoga and Karma yoga, the road of knowledge and the road of action.
According to the road of knowledge, you ought to be an example to follow. You don’t have to “spread” the knowledge just live in accordance to the Bhagavad Gita.
According to Karma yoga you ought to follow dharma and have no expectations to the fruits of your work. You work in order to serve a higher self or God if you like.