Click the user icon in the top right.
Click 'Notification Preferences'.
Active Notifications tab: Users can search for and delete any active notifications from here. Active Notifications usually includes any comment and discussion threads a user signed up for from a learning event.
Community Notifications tab: Users can enable or disable community notifications here. This will overrule the community setting (e.g., if the community admin. creates an announcement and sets it to notify community members).