Hi there and welcome Rosemarie
On the back of the Roku are three ports where cables connect to. One is a HDMI port which you connect to the TV. It's the flatter of the two ports.
The round one is for the power
The other square port is for internet. You connect a network cable to this port, and the other end to one of the network ports on your internet modem and it will then have internet.
Like in this picture.
Click me to view picture
When done, the Roku will then have internet.
If you would like any additional information or assistance, please do not hesitate to let me know.
Else if you can take a second to rate my service by clicking one of the stars at the top of the screen then submit, that would be greatly appreciated.