Most Helpful Girl
To clear all of your notification: Go to your notifications page (click on the bell icon) and then you should see the "Mark all as read" button in the top right corner.
To change your notification settings: Go to your settings page on your profile and if you scroll down, you will see a list of all the notification types. Uncheck the ones you do not want to be notified about and then click 'save.'0
Most Helpful Guy
You can change notification settings, should cull them down0