The Settings menu is where you can find all the game settings.
The first batch of settings is exclusively sound related, where you can mingle with the volumes, or mute them altogether.
The second settings tab is where you can do more things like reset your progress, delete your account, contact support, logout and turn notifications on or off.
Please keep in mind that resetting your progress and/or deleting your account will cause all your progress to be wiped, including purchases and unlockables.