No, but everyone can have one! If you are taking part on your own you only need to register and create a team of 1 with you as Captain.
If you want to enter as a group the Team Captain should sign up for an account. Team members should then register for accounts and select "Join an existing team".
If you need or want to change your team you can do so, but you will not take your score with you. That remains with your original team and you will become part of the new team with its existing score.