Plug in your Chromecast and turn on your TV
Make sure your phone or tablet is connected to the same WiFi network you want to use
Download and open the Google Home app
Tap the plus icon
Select Set up device
Choose New device
Select your home
Follow the on-screen steps to find and connect to your Chromecast
Confirm the code shown on your TV and in the app
Select your WiFi network
Enter the WiFi password
Wait for Chromecast to connect and finish setup
Test by casting from a supported app