The name of a form in the form editor, is the same as the title of the form when it displays to a user. 

If you want to edit or update the name of a form, from the Admin Dashboard, select Form Editor

Here you will see all your system's forms along with the current published state.

To make changes to a form, including changing the title, click into it from this list to go to the editor.

On the left hand panel of the form editor, click on the third "Form" tab:

You can no see the current form details, including the name/title of the form.

To change the name/title of the form, click on the pencil icon to the right of the current form name/title:

Enter the new title of the form and click the tick to confirm:

The name/title of the form will now have been updated, and will be displayed on the right hand preview pane as it will appear to users:

Remember to click Save after making any changes.