Lake Lamode

Walkthrough: You'll arrive in Lake Kingdom in a place called Lake Lamode. As you do, you will see the Broodal's Airship patrolling around the tower in the distance. This will be an indication to start heading that way, but a large wall actually separates you from them. After getting off of the Odyssey Airship, you can find some Purple Coins around the back wall, as well as a Power Moon by checking the shoreline for a shiny stone.

After that, speak to the Lochlady to learn exactly why the Broodals are there and what they are up to. From there, head into the water to find the stairs leading to the Plaza have been removed, forcing you to find another way to it. In the center of the water with be a musical note that you will start a chain that will eventually lead you to another Power Moon. On the opposite side of the water, use the plant to jump to a ledge that has more Purple Coins. There will also be an unusual stone on the ledge, but you won't be able to interact with it at this time.

From there, jump up to the main balcony across from the Odyssey Airship. Here, another Lochlady will advise you of a path down to the Water Plaza. She will tell you it can be found right behind her, but the only thing there is a blank wall. By examining the wall you'll find a zipper, so use Cappy at it to capture and control the zipper to unzip the floor. This will reveal a passage downward to an underground tunnel to the Water Plaza.

Once in the tunnel, ground-pound to sink lower into the water. Do this until you reach the bottom, watching out for the spikes as you do. Before moving ahead, grab the nearby Purple Coins. As you move forward and around the bend, you will see a bubble with the air Mario will need in order to survive. After obtaining it, head up the right side of the fork in the path to find a chest holding a Power Moon. After obtaining it, head up the left side of the fork in the path and defeat all the enemies that approach, eventually turning right to find Cheep Cheeps. Use Cappy to capture and control one of them, continuing forward with it straight into Water Plaza.