The first Moon Coin is floating above a small Donut Block at Point 1. When you’re ready, make a running leap through the Moon Coin just as the Lava Bubble drops out of your path.
The second Moon Coin is in a hidden area. Find the Invisible Block between the ? Blocks at Point 2, then climb up the revealed Beanstalk.
When you reach the top of the Beanstalk, follow the path to the right. Stand on the Donut Block directly above the Moon Coin. Wait for the Donut Block to give way, then grab the Moon Coin as you fall out of the area.
When you pass through the Red Ring at Point 3, a Coin Coffer appears and leaves a trail of red coins.
As you collect the red coins, watch out for the rotating fireballs. Jump over them and double back to grab the red coin you missed, or use the nearby Donut Blocks to slip under them.
The third Moon Coin is on a Donut Block between the platforms at Point 4. Slip between the fireballs as they emerge from the lava, grab the Moon Coin, and jump back up to the platforms.