Early in the level you'll see a purple warp box next to a Goomba. Hop in to start the timed challenge. When you start, run to the right to spin the stage You'll need to jump a couple times to get to ...

The first green star for this level is found in a secret pipe. You'll need to have a cat-suit to scale the wall. While jumping across rainbow rollers, you'll see two brown brick boxes. Jump on them to ...