I cant figure it out on how to get the test website running
If you’re running your web server, in most cases a port will be forwarded automatically for you that you can access to see your running application. You can read more about getting going with port forwarding: https://docs.github.com/en/free-pro-team@latest/github/developing-online-with-codespaces/developing-in-a-codespace.
If something else is blocking you, let us know what kind of application it is and what you’re trying to do. Or if it’s an open source project, share a pointer to the repo.