Thanks, but I’m an idiot. I dug around a little and realized I was low on disk space and running a badly outdated version. All good now.

Do some searches on “kiosk” software. That’s the general term of art for machines that are intended to run a single program/interface. As for distros, you’ll want something light and easy to maintain, ideally with automatic updates. Debian’s an obvious pick. Alpine could be great for something like this. Gentoo could be awesome too, but there’s a serious learning curve involved.

Did it currently have windows installed? If so, have you turned off secure boot and fastboot?

If you’ve done all that already, then maybe try adding nomodeset to the kernel parameters in grub. You can find instructions by searching how to set kernel parameters. It’s fairly easy, but kind of a pain to explain.