Your child should go to google.com and login with their school district account. Their login in is email@example.com
If your child has a hyphenated name, they will use their last last name.
Their password is their birthdate in all numbers - mmddyyyy.
Then in the top right hand corner, click on the nine dots and click on the classroom icon. Your child will already be set up in the Google Classroom that was made for them.