Help getting started with Roku devices, including setup, connecting your device to your TV, linking a Roku device to your account at my.roku.com/link, adding channels, subscribing to services, and more.
In regards to the device not turning on: What Roku device are you using? Is there a light on the Roku device? How are you powering the device? Is the device plugged into the TV USB port or is it plugged into a wall outlet with the provided cable and adapter?
In regards to the update: We recommend rebooting both your wireless router and your Roku device.
I'd also recommend trying to connect your device to an alternate network, such as a mobile hotspot, to see if you can update the device and finish setting it up. Then once the Roku device has been setup, try switching back to your home wireless network.