Is there a way for the person submitting the form to go back and make an edit, or is that feature only offered to the administrator on the back end?

Users who have submitted responses to your form can edit their responses at a later date.

Please refer to this guide: How-to-Let-Users-Update-Their-Form-Submissions-at-a-Later-Date

If you want to make changes/edit submissions after your user has filled out data, you can refer to this guide: How-to-Edit-Submissions-Made-on-Your-Forms