...and I can't figure out how to rename and/or delete one.

Is one of them obsolete and are you 100% sure which one it is? If so you can go to your websites list, by pulling down the little folder menu above the project files list, choose "remove website project" and that should delete it. Worse case scenario is you delete them both and reset it up. This won't delete your site files at all only the file that connects it as a project.

You can rename a project by renaming the .cpf and/or the .cpfs file and then in your project settings change it there too and that should fix that issue.

so you can rename it or delete it either way whatever you need to do