After you meet Kyogre in Withered Wasteland, go through the east area gate to reach Bleak Beach.
How to Reach Bleak Beach
After you meet Kyogre in Withered Wasteland, go through the east area gate to reach Bleak Beach.
Follow the Professor
Keep following the Professor until they stop at a broken bridge, and talk to them. Fix the bridge by putting blocks in the gaps.
Cross the Bridge
Cross the bridge and turn left, and you will see a broken Pokémon Center surrounded by water. Talk to Professor Tangrowth to continue.
Try to Use the PC
Try to use the PC in front of the broken Pokémon Center. Then go up onto the wall behind the Pokémon Center, and you will see a Horsea Fountain. Use blocks to stop the water from pouring on the Pokémon Center. After the water flows away, the PC will beep. Check on it.
Talk to Meowth
Meowth will run up to you, so talk to them. Follow them to their shack and talk to them. Then use blocks to stop the flooding in the shack.
Create Pokémon Habitats
Look around for Pokémon traces, then make the habitats you learn about if you have the required items. You can also use Water Gun to water the dry grass blocks, then use Leafage to grow four tall grass close together. This will create the Yellow Tall Grass habitat. Do this again so you have at least two Yellow Tall Grass habitats.
Talk to Meowth Again
After you get two new Pokémon to move in, talk to Meowth after they have a speech bubble above their head. Then make two Mushroom Lamps (you can find Glowing Mushrooms if you go back across the bridge that you fixed earlier; there are Glowing Mushrooms in a green area in the cliff wall) and put them in Meowth's shack. You can stand near Meowth's bed and press the right control stick like a button to see the outline of Meowth's habitat to make sure you put the lamps in the correct area. Talk to Meowth afterward.
Talk to Meowth About Mud
When Meowth mentions mud, talk to them. You will learn the Hydrated Yellow Tall Grass Habitat. Water the dry grass around some water, then use Leafage to create four things of tall grass at the water's edge, then wait for the water to splash. Check on it to meet Piplup.
Talk to Piplup
Talk to Piplup, then have them follow you, and face the blobs of mud in front of Meowth's shack. Piplup will create bubbles on the mud. Use Water Gun to wash away the bubbling mud. You can go around washing away all the mud in the area, but there is a lot of it. When you're ready to continue, talk to Meowth again.
Talk to Professor Tangrowth
After a while, Professor Tangrowth will mention being happy that there are more Pokémon. Talk to them and they will ask you to build a house for Pokémon. There are some houses across the bridge that you first repaired in this area. If you add blocks and doors, the houses will become habitable. You can then talk to Professor Tangrowth to continue.
Raise the Environment Level to 3
If the Environment Level is lower than 3, read How to Increase the Environment Level and take steps to improve the environment level until it reaches 3.
Rebuild the Pokémon Center
Once the environment level is at least 3, you can purchase a Pokémon Center Rebuilding Kit from the PC.
Help Meowth
When Meowth has a speech bubble about adding color, talk to them to learn the Chirp-Chirp Meal habitat.
Meet Torchic
There is already a Wooden Birdhouse, Table, and Plate across from Meowth's shack. Just pick up the plate and put it on the table, then put food on the plate, to create the habitat. When the birdhouse starts shaking, check on it to meet Torchic. Talk to Torchic and ask about making a Planter. You will need to find some Squishy Clay. Some of the blocks near blocks of sand in this area are clay blocks, and you can also find clay blocks in the cave where you first found Onix in Withered Wasteland.
Make Bricks
After you have some squishy clay, talk to Torchic to make some bricks. Check in with them after a while to get the bricks.
Make a Planter and Grow Flowers in It
Now that you have bricks, make a planter, talk to Meowth, put the planter in Meowth's habitat, then grow flowers in it (or you can use Rototiller to pick up some flowers so you can put them in the planter). Talk to Meowth to complete their request.
Talk to Piplup
When Piplup mentions needing more water, talk to them to learn the Trash Collection Site habitat. There is a trash can and sign near the workbench next to the Pokémon Center, and if you pick up any nonburnable garbage from the ground, you will learn the garbage bags recipe. Make some garbage bags and put them near the trash can and sign near the workbench, then when it starts shaking, check on it to meet Trubbish. Trubbish has the Recycle ability, and you can give them nonburnable garbage to get Iron Ore. There are other materials that you can give to Pokémon with the Recycle ability.
Get Iron Ore
After you meet Trubbish (see above), give them Nonburnable Garbage, then check in with them later to get Iron Ore. You'll learn the Shower recipe.
Make a Shower for Piplup
Talk to Piplup after you have the Iron Ore, then make a Shower and put it in Piplup's habitat. Then talk to Piplup to complete their request.