Hi Welcome to Just answer.
I will be taking care of you today.
What is the model of the Roku in question? How is the Roku connected to the internet?
There are few things you can try.
1. Disconnect power off the Roku, leave it for 10 Minutes and the connect it back
2. If you are using wireless router, disconnect power also and let the router sit for 10 Minutes.
3. After the wait, connect the wireless router first and then Roku.
ok thanks for the update. Can you watch anything from it?
Please reset the Roku to factory setting as below:-
Once the factory reset is completed, then try to update the software
How long have you owned this? How far is the roku from the wifi?
There are other things here that someone has succeful correct the problem.