First see the dedicated subforum for the My Cloud Home. This subforum is generally for a different device, the single drive My Cloud.
The My Cloud Home must be connected via Ethernet cable to a router, switch, or even a computer in order to be able to access the data on it.
I assume (not having used a My Cloud Home) that like the My Cloud, one could use the My Cloud Home without having a live broadband connection. It would only be accessible by those devices on the local network.