Hi Komali ,
You can use the leave action widget which will execute when the user leaves suddenly , In that microflow you can have your logic for particular user and you can open respective page for him when he login again
So you need an entity between user and course, for instance CourseProgress, in which you save the progress. Every time the user advances to the next subject or page, update the CourseProgress object. If a user clicks on the course a second time, retrieve the right CourseProgress object, and direct the user to the correct page in the course.