My advice would be:
Dig out the 'Quick Installation Guide' leaflet that came with the drive.
Follow the instructions for 'Mobile Devices' (even if you're using it with a desktop PC).
These instructions take you to a much more rational setup procedure, using the control interface (the 'Dashboard') built in to the device.
As Bennor says, you would also benefit by reading the User Manual first.
Read pages 1-11, as far as the heading 'Getting Started Using the Online Setup Installer', then skip to 'Getting Started Without the Online Setup Installer' on p21.
When you get to the end of Chapter 3, skip to Chapter 6 'At a Glance: The Dashboard'.
Only when you have your device basically installed and running as a NAS would I suggest reading up about using the various WD apps.
Note that these apps are entirely optional for local use; the backup and sync apps may better be replaced by generic, free apps, such as FreeFileSync.
Depending on your priorities, you should then read up on:
- backing up your devices to the NAS
- backing up the NAS to another storage device
- setting up and using Apple TimeMachine
- setting up and using the media server
- setting up and using remote access