If you did not pass the course with the grade required to earn a verified certificate, you can enroll in a future session if it's offered again. Most edX courses repeat in new sessions. Please note you will need to pay the verified certificate fee again.
Note: Un-enrolling from and re-enrolling in the same course session won't reset your course progress.
Each course team sets a fixed number of attempts on each graded assignment. Once you've used up all available attempts on an assignment, it isn't possible to retake the assignment. It's also not possible to reset your Progress score. You'll need to wait for a future session to retake the course.