All operations as a captain need to occur after you are logged into the system.
Your league will provide you with a website address. This is specific to your league. It will land you on a page that looks similar to this.
The menu button in the top left will pop open a menu of options providing you access to everything your league website has for you to view.
And one of the options in that menu is to login.
You then get the login form. You need to remember how you registered your account. If you registered with Facebook or Google, then press that button to login. Alternatively enter your username (email address) and password.
If you cannot remember your password, press the Forgot Password button to start a process of resetting it.