I've been having this problem for about a day now and I don't know what to do. Can someone Please help me
You can download Unity Hub from this page: https://unity3d.com/get-unity/download This link will bypass that page and download Unity Hub directly to your Mac Downloads folder: Download Unity Hub
Check the file size. My experience with OSes is that they label a file "damaged" when it hasn't properly downloaded. Most likely when the download claimed it was "done" it wasn't actually done but simply stopped without finishing.
That's not possible from 2019.1 and forwards. Launching Unity.exe just opens the hub, the built-in project launcher has been removed. You can still open a project directly, by passing it to unity.exe on the command line, but that's not really a long-term solution.
@coolcraft12312 : Was the issue fixed for you ? Try downloading it again and if it didn't work please tell us so we can debug you.