Once in the Team section just click the Create Team or Create Multiple Teams button in the top right corner.
You can create teams in blocks of 10 and just need to choose the sport type, and associate the teams you are adding to a league, division and season.

To generate fixtures for your league, teams need to be associated with a league, division and season.

Once you have setup the season, the next step is to create your fixtures. Click on the option below to get started!