First, I have to tell you the truth that the built-in apps on your Mac can't be deleted. If you can't delete apps from the Launchpad, you can go to Finder to do that. Open Finder > Applications, then right-click the unwanted app and select Move to Trash or directly move it to Trash. However, this deletion action won't completely delete the associated files of that app.
If you still can't delete apps from Mac Finder or want to delete both the unwanted apps and all their leftovers, you are suggested to use a professional tool.
iBoysoft MagicMenu is a right-click enhancer that contains the app uninstallation feature. You can use it to right-click to uninstall apps on your Mac along with all their associated files. Then, you won't need to spend a lot of time searching for the deleted apps' leftovers on your Mac.
- Download, install, and open iBoysoft MagicMenu.
- Select Extension and then click the download button next to Uninstall App to add it to your right-click menu.
- Right-click the app you want to delete and click Uninstall.
- By default, all contents of the app are selected, you only need to click Delete to permanently remove them from your Mac.