The first Star Coin is floating at Point 1. Stomp one of the nearby Koopas and bounce up to collect it.
There’s a row of three Invisible Blocks located between the pipes at Point 2. Wall jump up to the Invisible Block in the center of the row to find a 1-Up Mushroom. Allow the 1-Up Mushroom to drop to the ground before you reveal the remaining Invisible Blocks.
The pipe at Point 3 leads to a hidden room. Drop down to the pipe, collect the coins from the Invisible Blocks above you, then enter the pipe to find the hidden room.
After you pass through the pipe, stomp the Buzzy Beetle and throw its shell into the Block at the top of the room. When the shell drops down to the first POW Block, follow it through the gap.
Dash along the Blocks to the right before the shell destroys them. As you approach the last group of Blocks, make a running leap up to the Star Coin.
The third Star Coin is located below the platforms at Point 5. Stomp the nearby Koopa and throw its shell at the Star Coin to collect it.