1. Go to classroom.google.com
2. In the top-right-hand corner of the Courses page, click on the + icon.
3. Choose 'Create class'.
4. Tick to say you've read the notice and click CONTINUE.
5. Enter the course name. Plus, you can add further information but it's optionally. The section part is shown as a sub-title in the course. Click CREATE.
6. Your course will be created and you'll be taken to the stream page.
On the Courses page, you can see it's added the course.