Translation to English: Hi, I don't know how to use multiplayer mode.

Help.
My answer in English:
To play Stardew Valley multiplayer, choose "Co-op" from the main menu, then create a new farm or join an existing one, make sure you have cabins for all players, and set your desired economy options.
Here's a more detailed breakdown:
Starting a multiplayer game:
On the title screen, select "Co-op" instead of "New."
Choose whether to "Host" a new farm or "Join" an existing one.
Hosting:
Click "Host New Farm" to create a new multiplayer world.
Decide the number of starting cabins (to accommodate players).
Optionally, set a profit margin and whether players share a wallet or have individual wallets.
Joining:
If you're joining a friend's farm, you'll need the host's IP address (for mobile) or a code (for PC).
Enter the IP address or code and select the farm from the list.
Key Considerations:
Cabins: Make sure you have enough cabins built for all the players joining.
Economy Options: Decide whether players share a wallet or have individual wallets, and adjust the profit margin to your liking.
Split Screen (Local Co-op): If playing on console or PC, build cabins for each player and connect the controllers.
Mobile Multiplayer:
On mobile, to host a game, click "Co-op," then "Host," and select a saved game or create a new farm.
To join, select "Join," then "Join LAN Game" and enter the host's IP address.
To find your device's IP address, go to Settings > Wi-Fi, click the blue (i) symbol next to the Wi-Fi network you're connected to, and scroll until you find the IPv4 address.