I need a writing strategy

I was able to sit down and do the Zette's Gym challenge, but every time I try to start Chapter 3, I stall. So here's my thought:

Approach each scene as a Gym challenge. Set a task for the characters to achieve during that scene, specific or general, doesn't matter as long as there's a goal to aim for. If I can do one Gym, I should be able to do a number of 'em and then string 'em together.