If you select the three dots in the upper right of the classroom in question you will see the options to:
If you choose to archive it, the class will then be moved to the archived section (under the hamburger - the three lines in the upper left of your screen). This class can always be "brought back to life" if you desire.
If you copy it, please note that what it does it makes a copy of everything in the Classroom (just not the students). Every document, video, including your directions, course syllabus, and other 'view only' documents you provided to your students in their assignments. However, they are in draft form so you can use as you see fit.
Personally, with a new school year, I like archiving the class and starting from scratch - but that is up to you.
One bit of advice I have when starting your class is to make your stream be streamlined by removing the notifications of classwork being posted in the stream. I like the stream being clean ad only for announcements you make. Remind the students to always go into their classwork to see what their classwork is. Of course these are just my 2 cents.
Reminds me of Steven Wright's joke:
"Why is it, "A penny for your thoughts,"
But, “you have to put your two cents in?" Somebody's making a penny. 😀
Embedded below is a 2 minute and 8 second YouTube tutorial I created.