Hi, you'd select Hulu on your TV. Chromecast is only if you wanted to open an app on your phone and "cast" it to the TV.
Once you open the Hulu app, you should be prompted to sign in. Once you enter your login information (email address and password that you used to create your Hulu account), you should be able to watch.
Thanks for the help, scythe944 and Jeran.
VondaLee, you can also check this support website article to learn more about how to cast to your TV with Chromecast built-in. Feel free to let us know if you still have questions and concerns. We're here to help!