Hello @ER1N ...
In your personal user files area of Canvas, you have a "Submissions" folder that has a little padlock icon on it. Any file submissions for assignments in your courses automatically get placed in this folder, and the padlock means that you cannot delete any files within that folder. Files in this folder do not contribute to the available storage space you are allowed for personal file storage. You can read more about this in How do I view my user files as a student? - Instructure Community (canvaslms.com) under the headings "View User Files" and "View My Files". To my knowledge, there is no way to disable what you call an "auto-upload" ... as this is part of the normal process when students submit work to their instructors.
I hope this will help to answer your question. Sing out if you have any other questions/concerns...thanks!