When you boot up the device, the screen will you the dashboard.

To access the WI-FI setting, tap on the control panel button on the top right corner of the screen

*This is control panel close up*

You can set the connection device by simply tap the three dots next to the "WIFI"

You can disconnect from your current connected device by tapping on the three dots on said device name.

You can use Control Panel to adjust volume of the touchscreen by swipe left and right as decrease and increase