Hard drive issues MacBook Pro

Hello there, I recently got a 2 TB external hard drive for my birthday, and I have been trying to install RetroArch on it. I have tried to drag the applaction and the “RetroArch” folder, but whenever I run it, it starts to have black squares instead of the regular markers. I have heard I need to configure something, so can someone give me a step by step explation on how to do it? Thanks

When you first open RetroArch, scroll down 2 entries to “Online Updater” and select it with the Enter key, then Scroll down 4 entries to “Update Assets”. Give it a few moments to download and extract. Your icons should show up now. You’ll probably want to “Update Databases”, and then grab some Cores also.

Did not work for me.