Welcome to the forum.
Is there a plug in that will allow this version to open/save MP3 files?
Where can I find that?
The MP3 plugin for CEP1.2 had to be purchased as an extra, and it hasn't been available for many years now, I'm afraid. I didn't bother with it - I just used CE2000 instead when I wanted MP3s - MP3 creation was included free with that!