Spark - why the initial team and docs?

I would like to use spark with team functionality engaged. To do this, my thoughts were that a user would create an account and then create their own teams and/or join other teams. I don't understand why an initial team is required to have a user register. Am I not really understanding what the team system is for?

Also, I can't seem to locate a lot of the documentation for spark. It notes that I can set up accounts to bill by the team user. Where does it explain how to do this? Where does it explain the effects of team roles on what users can and cannot do on a team - or is that simply something I am expected to handle?

I feel like I am simply missing some of the documentation.

Thanks