Once you have created your teams, you can now add your participants.
Navigate to your league and select '+ Add participant'
If they are an existing contact, then you can select 'Existing contact' and search for their details, if they are new to your site then you will need to complete the form. You will also be able to assign them to a team.
If a participant has registered for the league from your website then they will appear in your list of participants as 'Unassigned'
To assign them to a team, select their record, a summary of the players details will appear and at the top of the screen you can select from the drop down list which team you would like them to play in.