Thanks for your first post and welcome to our forums page.
Very sorry to hear you are having trouble viewing these channels through TV Go.
To watch Sky Sports, you would need to have these included in your package and also would need to download the Sky sports app. There is an option to log in using your Virgin Media log in details so you can view these channels. You can then either access this through your Virgin TV Go app (which will then take you through to the Sky Sports apps) or you can go directly to the Sports app and use your Virgin Media online account details to log in.