I imported my private MP3 collection (basically ripped from the CDs I bought years back) on my Mac into iTunes some years back. On my "Music" directory, I basically see my folder
private, where I put my MP3 files with 15 GB, and iTunes, also with 15 GB. I guess that is where iTunes stored all the data after import.
I use the Music app126.96.36.199 on macOS Catalina 10.15.6 now instead of iTunes.
I am about to replace that old Mac book with a new one. My plan is to copy that private folder onto the new machine, and import again but I worry it won't that like "double" all the existing entries.
I saw this very old question, but I am rather looking for a more basic explanation about "option space", and best practices.
How do I get the same MP3s into Apple Music these days?