If you want to add games to your team schedule that are not in the league, SportsEngine will not allow you to add the game unless the team is in the system.
So, if you play a non-league team in an exhibition game, and they are not listed here, send an e-mail to firstname.lastname@example.org with the team name and I will add it here. Then you can choose them as an opponent and add the game to your schedule.
Don't worry about levels (10U, etc.) DON'T FORGET to select "game does not count in standings" when you add the games!
If you play a team that is in the league, but it is a non-league exhibition game, just select the team from the league but be sure to select "game does not count in standings."