Hello there, Aichels.
It sounds like you are wanting to disable notifications on your MacBook Pro, running El Capitan and you are still seeing notifications. The following Knowledge Base article outlines the features and settings for Do Not Disturb:
OS X El Capitan: Receive or stop notifications
You can set options in Notifications preferences to turn off notifications for specific apps or to pause all notifications. Choose Apple menu > System Preferences, then click Notifications.
Turn off notifications for an app: In Notifications preferences, select the app on the left, then choose None for the app alert style on the right. You no longer receive any notifications for the app.
Stop notifications during specific hours: In Notifications preferences, select Do Not Disturb on the left, then set options.
Pause notifications until midnight: Hold down the Option key while you click the Notification Center icon in the menu bar.
When Do Not Disturb is on, the Notification Center icon in the menu bar is dimmed. You don’t see or hear notifications arrive; they are collected in Notification Center where you can view them later.
Use Notification Center
Set sleep and wake times for your Mac
Thanks for reaching out to Apple Support Communities.
Kind Regards.