The team management screen allows you to add national federations and to create your own teams.
On this screen, first we see the federation list. If you want to use a federation you have nothing to do, just validate after you choose the country.
But if you want to create one or more teams in a country you must enter the team name and the abreviation. For example, if you have two French teams you must choose the country (FRANCE) then enter the club name (e.g. CLUB FR 1) and the abreviation name (e.g. FR1).
If you want to add a club, you must choose a federation and choose a club. After that, the name and the abbreviation club will appear in the fields.
After you have done this remember to save your new team.