Save mp3 files from email attachment to iTunes

That's an amazing dialog; I confess it sort of went over my head. And it's not helping me with my issue: I am receiving mp3 files (recorded choral music) in email. If I click on the attachment, it begins to play in iTunes. But at this point I haven't saved it anywhere, which may be needed if I want to go back to it. Otherwise, when I click on the name in iTunes, it cannot locate it. Where to save it? Is it really "c:\users\[computer name]\Music\iTunes\iTunes Media\Music\[Artist Name]"? Then, when it appears in iTunes and I want to change the title, etc., it's not accepting my edits. This is on a PC running Windows 10 and iTunes.