The default setting in Canvas is to restrict editing of pages to Instructors only. However, Instructors can allow students to edit pages. If you can edit a page in your course, your instructor has allowed you to contribute content to the page.
When you can edit a page, you can also view the history of a course page.
Pages is designed to open to the front page for the course, if there is a front page selected. Click the View All Pages button to select a page from the Pages Index.
Click the Edit button.
Note: You will only see the Edit button if you are allowed to edit the page.
You can notify users that content has changed by selecting the Notify users that this content has changed checkbox . Click the Save button  to save your edits.