Hi arlecia and welcome to the Canvas Community! What type of assignment is this? If you submitted answers to a quiz then you would need to be allowed multiple attempts to resubmit questions. If this was an assignment where you attach a document or fill in answers in a text box, then you should be able to resubmit the assignment but there is no way to go back and edit what has already been submitted. Both versions would be visible to the instructor grading the submissions but the most recent submission would appear first.
I hope this helps and best wishes!
Retrieving data ...