welcome to just answer. I would like to know the model of the roku you're trying to use.
Sorry for delays. I am not sure I can provide an answer without knowing the model of the roku.
In a general way, the roku is connected to the tv through hmdi cable. Your tv should have at least 2 hmdi inputs.
Once connected, turn the tv on, select the input where roku is connected then turn it on and follow on screen set-up instructions. You will need a wifi user name and password ***** input on the roku to connect on the Internet.
Here is the link to set up the roku