I initially set up a JIRA Kanban board and would now prefer to convert to a Scrum board...is there a way to do this without having to re-create the stories and epics that currently exist on the Kanban board?
In JIRA boards are simply views on projects. It is the projects that contain the stories, epics and other issue types.
This means that you can create a new board that points at an existing project.
Say for example your original Kanban board was called 'Team X'. When that was created it would have created a project called 'Team X' as well. The board would be a view on this project.
You can now create a new board of type Scrum. Make sure that when you create it you chose the option 'Board from an existing project'. Then select the project that you were using previously (in my example it is the one called 'Team X').
Now you have a Scrum board that shows all the issues that were on your Kanban board.
You don't even need to get rid of the Kanban board. Both of them will still work.