Wifi Dongle

I am planning to buy a WD My Cloud. But I have a question first.

Is it possible to connect a Wifi Dongle to it so I can make it connected to the network wirelessly?

No. The usb port mounts only usb flash and usb disks. 

I’ve tried to connect 2 usb wifi dongles but they are not recognizable.

The only way to make your cloud device wireless is to connect it on a wifi router

Since it is linux-based, you can do pretty much everything with this USB (but will loose garanty). So far people hooked wi-fi and USB sound card to MyCloud and MBL.