Hey there lorbac57,
From the information provided in your post, it seems like you are still using the same computer that you originally imported the CDs to, is that correct? If so, you can go ahead and update iTunes since this process does not affect your iTunes library files:
Get the latest version of iTunes - Apple Support
https://support.apple.com/en-us/HT201352
Just to be safe, you could always backup your iTunes library:
Back up your iTunes library by copying it to an external drive - Apple Support
https://support.apple.com/en-us/HT201625
However, if you situation is that you have two computers, one with an old version of iTunes (along with all of your imported music from CDs), then you may want to consider using Home Sharing to transfer these files from the old computer to the new one:
iTunes 12 for Mac: Use Home Sharing to import items from another iTunes library
https://support.apple.com/kb/PH19614
This is only one method for moving your iTunes library to a new computer. Here is another link with other options for moving your iTunes library to a new computer:
How to move your iTunes library to a new computer - Apple Support
https://support.apple.com/en-us/HT204318
Hope this helps resolve your issue. Thanks for coming to the Apple Support Communities!
Cheers,
Braden
