Is it possible to have many to many relationships between custom field sets?
I think, if I'm reading your question correctly, that what you want to do does not require anything custom. I would do it this way:


Create an event in CiviEvent. This will have the fields name, date, location, etc already available for you to fill.
Make this event a certain "type." The built-in options are things such as workshop, meeting, and class, but you can add a type called "team."
All the events of type "team" are easily searchable and viewable. 


Is this what you were going for? If not, please describe in more detail what it is you are trying to do.