You will not be able to do anything in game until you register your Discord account with your Steam account.
You will get an in-game message telling you to register in Discord with a OTP.
After you get this message go to any Discord channels and use the command /register and enter your OTP.
Discord bot will confirm the registration, and shortly after it will be confirmed in-game.
Register new Discord account
Use /registerdiscord to request fresh instructions for linking your Discord account.
While connected and authenticated to Sunshine Alley, enter /registerdiscord in chat to request an account-link code. Follow the instructions shown in game chat and enter the exact /register command in and Discord channel. The command requests the instructions; linking is completed in Discord.