The default Home page in Canvas is set to be Modules. If you have not used Modules before, a brief overview is attached as a PDF at the bottom of this article. More extensive documentation is also available by checking the section on Modules in Canvas' documentation for instructors starting here in their online instructor's guide.
If you prefer not to use Modules, however, there are other choices to set as a Home Page: the Syllabus page, the Assignments page, the Recent Activity Stream or a page that you have created on your own. You can change it to one of these other choices by following the instructions given by Canvas here: How do I change the Course Home Page?
To create your own page with text of your own that you can make your course Home page, you must first create a page from the Pages menu item. After you create AND publish the page (a page must be published before it can be set as a Home page), you must then head back to the Pages menu item and set that specific page that you created as your "Front Page" by following these instructions: How do I set a Front Page in a course?
Once you have set a specific page as a Front Page, there is one final step: head back to the Home page of your course site and then change it to a "Pages Front Page" as shown here.
If you want to use Modules as your Home page, it requires knowledge of Modules, which is introduced in the attached PDF document.