is it normal for my MacBook to have over 56 GB on OTHER files? How do I clean it up? I am getting a message that my disk is almost full. I don't have enough space to download and install the latest update.
MacBook Air 13″, macOS 10.15
Apple menu -> About This Mac -> Storage -> Manage can help you identify the largest files on your system.
Copy these files off to external storage if you need them.
As others have said, keep out of the Library folder unless you know what you are doing.
How to free up storage space on your Mac - Apple Support
"Other" storage is also well explained here.
See used and available storage space on your Mac - Apple Support
i cleared out a bunch of GB email files by :"go to folder:": ~/Library/Containers/com.apple.mail/Data/Library/Mail Downloads
Doing something like snowleapard2020 suggests, involving clearing files out of a Library directory, is extremely dangerous. Library files may contain cross-references that involve other files and/or applications. For example, the specific operation snowleapard2020 performed will interfere with the Mail application. Similar cleanup could have been performed much more cleanly by doing it using the Mail application to delete mails with large attachments.
How do I clean up the disk ?
