Can I watch with Chromecast?

To cast from one device to another they both have to be on the same WiFi network.

Cast from your computer:

1. Open Google Chrome

2. Click the three dots in the top right corner.

3. Click Cast...

4. Choose the device you want to cast to.

Cast from your Android device:

1. Open the Google Home application

2. Choose the unit you want to cast to.

3. Click Cast my screen -> Cast screen.

Read more https://support.google.com/chromecast/answer/3228332