Cisco webex is already installed on your laptop

Sign in with your email format in the first window and press Next

Now it should open a new window, asking you to login with email address again, this time type in your

This will take you to a 3rd window, where your email address should be automatically filled in already, and you just need to type your password (Same you use for Outlook etc.) and then press "Sign In" 

And now you're logged in