It's Wireless unfortunately... do I need an adapter to get the Xbone controller to work?
You can't connect xbox 360 controllers to pc without the receiver, but xbox one controllers can be connected with a micro usb cable (most phone chargers these days have them as charging cords). Download the driver packages from here. I've never done this, so I can't help you after this point but I'm sure it can't be too complicated.
Got controller and rocket league working, will play online with you guys when I get ethernet ran through my house a week on saturday.
Steam is senseikitten