To manage up your PS4 Save Data, go to [Settings] > [Application Saved Data Management] > [Saved Data in System Storage]. From there, you will find 3 options:
You can manually upload saved game data from a PS4 system to the Online Storage for your PlayStation Network account. Uploaded saved game data can be downloaded later to continue playing games without starting over. To use this feature, you must subscribe to PlayStation Plus.
Here's how it works:
You can copy saved data to a USB storage device that is connected to the PS4 system. Saved data that you copy can be used as a backup, and you can copy saved data from the USB storage device to another PS4 and continue playing a game. Note that you must be signed in to the PlayStation Network to use this feature.
This lets you delete saved game data from your PlayStation 4.