The whole "teams" thing is just a marketing scheme. -_- It just encourages you to buy shirts with your Team character on in it, all the while forgetting about the subject matter of the actual movie/books. Yes, the romance is an important component of the series but it is not what the book is about. Don't forget that these people are fighting for their lives.
That being said, I won't be one of those douchebags that ruins your fun, but getting hung up on "who will she choose?" is an injustice to you. The series has much more than just that to offer, which is why it is such a great story.