To connect the Google Chromecast to your Television you plug one end of the USB power cable into your Chromecast and the other end of the cable into the power supply.
Then next use the USB power cable and power adapter that is included in the box for optimal performance and then plug your Chromecast into any open HDMI input on your TV.
After that Plug the power supply into an open outlet.
Then you'll need to enter details such as your wifi password etc to connect to the Chromecast device through your Wifi router and connect the device you want to cast from.