This stage is Ty-foo Flurries (6-5). This complete walkthrough will provide you with a 100% video playthrough and a screenshot of where you can find all the green stars.
Game Play Walkthrough Video
Green Star 1
There’s a cliff overlooking the spikes where you found the Stamp. Jump directly under the star to reveal a secret block. Watch out for the wind as it can push you into the spikes.
Green Star 2
Grab an Ice Skate from a Goomba to pass the spikes to the left. You will enter a purple mystery box where you will have to race with Ice Skates. Get to the end of the course and claim your second green star.
Green Star 3
You won’t miss the third green star. Time your jump and the wind and grab the star without falling and die.
Grab the Ice Skate from Goomba and pass through some spikes, go north and get the stamp for the stage.