Personally, I recommend starting with Puppy Linux. It’s small enough to run completely in RAM, so it doesn’t matter how slow or malfunctioning the hard drives on the old hardware are, it just works. If you can then use it to prove out the state of the hardware, you can upgrade to a larger distribution.
In addition, running in RAM is FAST. You’ve heard Linux can rejuvenate your old hardware and make it fast again? With the small distributions, that’s true!
This is a guide to Puppy and the other similar small distros, arranged from large, medium, and small.
14 Lightweight Linux Distributions to Give Your Old PC New Life https://www.makeuseof.com/tag/6-lightweight-linux-distributions-give-pc-lease-life/