You can upload PDFs to a page in Canvas.
Pages is designed to open to the front page for the course, if there is a front page selected. To select a page from the Pages Index, click the View All Pages button.
Insert PDF Link
In the Rich Content Editor, place your cursor where you wish to insert the PDF document.
View PDF Link
Look in the Rich Content Editor to be sure that the file was properly inserted where you left your cursor. If you look closely you will see the file name flash yellow the moment it is inserted in the page.