Does my league have to be full? Can I have an odd number teams?

You can play as long as you have at least 4 teams (the maximum is 24). As soon as any league has 4 teams in it, it can conduct a live draft, email draft, or the commissioner can import rosters.

You can also play with an uneven number of teams. In head-to-head leagues with an uneven number of teams, one team will have a bye every week.