Thanks for help!
How repaired hdd in old osx 8.6 mac i386.
A live usb with debian 10.9 buster did it asked to change from Bios boot to Uefi boot & reinstalled hdd. Laptop works. So now can put distro in usb, & try which debian based distro works best on Mac osx 10.13.6. MX, PsychOS, Manjaro, Debian?
I liked the software setup in Psychos; many writing tools in it.