Deleting an App
I downloaded whatsApp to my Mac and I wanted to delete it, I pressed the choice eject however, since this my first time using a Mac computer I wanted to know if that's a way of getting rid of apps in the Mac.
MacBook Air, macOS 14.0
Uninstall apps on your Mac - Apple Support describes the basic steps.
It sounds as though you were attempting to eject a disk image (.dmg file type). That will eject the disk image used to install an application, but it does not uninstall the application itself.