Are you wanting to hide the previous school year’s posts on your class blog? Well, here you are the steps to make that happen.
Log into the Dashboard of your blog.
Click All Posts on the left side menu.
Check the box next to Title right above your post listings. This selects all of the posts on that page (roughly 25 posts).
Change the Bulk Actions box to Edit.
On the right side of the box that popped up, you will see an option to change Status. Change that to Private.
Click the Update button on the right.
You will need to advance to the next page at the bottom of your post listing and repeat the process above if you have more than 25 posts to hide.
FYI: You can make previous posts public again by click the box next to that post only, and then follow the steps above. Instead of checking Private, check Published.