ISO 9660 (Joliet) CD
I understand about going into disc utility to then open the files up, however when I have done this all files are not able to be opened up, like auto run.
Question marked as
You use the Finder to access the files on a CD. As for the "Autorun" file, this file is meant for Windows' systems to automatically run some predetermined program usually to provide a menu or to launch the Windows installer for the included Windows software. It is not meant for macOS.
If the CD is meant for both Windows and Mac, then look for a ReadMe file which may provide instructions on how to use the CD. Sometimes a CD will contain an index.html file for access to the instructions.
If you need more assistance, then you will need to provide more information such as what the CD is for and perhaps a screenshot of the files shown on the root of the CD.