If your teacher imported you through Google Classroom, you should log in by clicking the "Log in with Google" button on the CommonLit login page.
The first time you log in, you will see the "Your Account Needs Updating" page and be prompted to create a backup CommonLit password and your grade level. You set the backup CommonLit password in case you are ever unable to log in through Google. Be sure to set a password that is easy for you to remember, but hard for others to guess.
After saving your password, you must click the "Connect To My Google Classroom Account" button. You will not be able to take an assignment linked to Google Classroom until you connect to Google. If you miss this page, don't worry - you can connect to Google Classroom from your My Account and Classes page as well. We will also prompt you to connect when you go to begin an assignment if you haven't successfully connected yet.
That's it - you're all set!