Passwords apply only to users who have linked their game via their email address; if you linked via Facebook no password is needed for the game, as long as you are connected to Facebook.
You can reset the password, by using the "forgot password" option in game by doing the following steps:
- Tap on "Settings"
- Tap on "Login with Email"
- Tap on "Already have an account? Login" at the bottom of the screen
- Tap on "Forgot password"
- Enter the Email address you used to associate with your team and you will get a temporary password in your Email.