macOS has two different types of Library folders. One is the system library folder which you really shouldn’t mess with unless you know what you’re doing. The other is the user Library folder and again, you really shouldn’t mess with it but doing so is less damaging than messing with the system Library folder. In both cases, since the folder is an important one, it is hidden. You can view it by opting to show hidden files and folders on macOS, or you can permanently unhide the user Library folder. Here’s how. https://www.addictivetips.com/mac-os/permanently-unhide-the-user-library-folder-on-macos/