Retrieving my music library
How can I download my music library in iTunes on Mac 10.6.8 to a memory stick without subscribing to Apple Music?
You can copy locally stored media to a memory stick, by dragging and dropping from the iTunes interface to a folder in Finder. In more recent versions of iTunes/Music it may be necessary to use an intermediate folder on the desktop for example, or work completely within Finder. You should be able to download any unhidden past purchases that are currently stored in the cloud. If you're having problems downloading past purchases or accessing your iTunes account then it may be that Snow Leopard is now too old and cannot connect to the iTunes Store using modern security protocols. If this is the case you will need something newer, e.g. El Capitan or better, to access your purchase history.
tt2