You require access to an active Xbox Live account to play Bleeding Edge online, offline content such as the tutorial and dojo can still be accessed.
If you want to post on the forums you will need to login to BleedingEdge.com with your Xbox Live account details.
If you're having trouble accessing your Xbox Live account or you simply cannot remember your password, you can find recovery steps and more helpful information via Support.Xbox.com
Don't have an account? You can create an Xbox Live account via your Xbox One console or Xbox.com