Plug the smaller end of the USB power cable into the Chromecast and the larger end into the power supply, which can be plugged into an outlet, and plug the Chromecast into an open HDMI port on the television. Once it's plugged in, the Google Chromecast home screen should appear.
It is important to use the cords and adapters that came in the Google Chromecast box for optimal performance. If there are no available outlets near the television, the USB can be removed from the power supply adapter and plugged directly into an available USB port on the television. In addition, if the Chromecast won't fit into the television's HDMI port, or if the Wi-Fi reception is poor, try using the HDMI extender that came in the box. If the Chromecast home screen doesn't appear on the television screen after trying all of these steps, use the input or source button on the remote control to change the input channel until the Chromecast home screen appears.
Be sure that the television is high definition, or it won't have an HDMI port and won't be compatible with Chromecast. Also, make sure there is access to a secure 2.4 GHz wireless network. Lastly, make sure there is a compatible Android or iOS smartphone or tablet or Mac, Windows or Chromebook computer, which will be needed to use Chromecast on the television.