I am sharing this folder of mp3 with a friend, and I read and just burned the folder using the Catalina finder system, by right clicking and burning.

I can open and see the folder and mp3 files, but info says it is Mac OS Extended

Will this be readable on a PC?

And if not can FINDER burn a PC readable DVD data disc?

Windows cannot read Mac OS anything format.

I used to do ISO 9660 with Toast back in the day for audio discs, maybe Finder has some provision for that as well? Never tried.

I don't know the answers to your questions but, have you tried formatting a USB Thumb Drive as "exfat". That would get you around the 4GB file size limitation and should be readable by a PC. If you already have a thumb drive you're not using, there'd be no cost (as opposed to a paid App like Roxio).