You should just be able to plug it in then load the KHUB.rom file via the usb port and make sure you have the latet bin in your Kbox. Check your network settings to make sure it is set for dhcp and the AU setting for Echostar is off. Power cycle the Kbox and that should do it.
You can get a 5V 1A rated power supply separately if you do not have one. The k1Plus does not power the khub, and even the black hub you bought will require the above rated power supply if used with k plus. The proper power one should say 5V 1A.
A little more explanation on the 5V 1A power supply. If you have say a 4.5V, it may or may not work but will not do any harm If you have a higher voltage power supply, upto 6V you are safe. Beyond that it may do damage. If you have a 5V 2A supply, it will be OK If you have 5V 500ma supply it may still work but may cause problems - however it will not do any damage.