When you receive unwanted notifications from an app, touch & hold the notification, then touch Stop notifications.
To review all apps and adjust whether they can send notifications:
Do one of the following:
For each app, you can control how urgently that app's notifications alert you when they arrive. You can choose between having notifications:
To change the urgency of an app's notifications:
To adjust the volume level of all notifications:
To change the sound for all app notifications:
Do one of the following:
To change the notification sound for a specific app:
Touch the category for enabled notifications, then touch Advanced > Sound and select a unique ringtone, or set it to none.
If you don't see Sound, touch Behavior and select an option that includes sound.
To let an app's notifications be heard when Do Not Disturb is on:
If an app isn't sending notifications but you want it to:
App icons show dots to alert you about unread notifications. You can turn off dots for one or all apps.

Turn dots off for all apps
Turn dots off for one app
If you've set a pattern, PIN or password, you can prevent lock screen notifications from revealing private information.
To adjust notifications for all apps:
Do one of the following:
To hide sensitive content from specific apps:
Types of notifications the app sends appear here. For each enabled notification that you want to hide: