Good on you OP for letting all these autistic people genuinely feel like they are telling someone about linux for the first time.

There's love in this world <3

Oh! There‘s probably someone who wants this to play a specific game they have lying around as a CD-ROM. Nerds are like that, always needing the time appropriate hardware for their games.

Yes, I do own a low latency CRT TV to play smash melee, why?

Obligatory Lemmy answer: Install Linux.

Seriously, though, it's a great way of learning if you decide to set it up as a NAS

As much as I would love to see things repurposed, this thing is a dinosaur, and you’d be better off for both yourself and the environment to just recycle it and get a Raspberry Pi or something which can probably run circles around it at 10% of the power budget. You don’t need to keep something old to learn something new.

Set it up with netBSD.

Connect some large drives to it and use it as a file server.

Host something on it such as matrix or if you have enough ram a game server.

Use it as a retro game console, a quick look at the specs online suggests it should be able to run PS1 games and older fine.

If you're into home automation, you could use it as a command and control center.

Could be used as a jellyfin server but you'd potentially need to transcode everything in advance.

Plex server. Especially good for parents if you have digitized movies and music.

If you don't need it, secure wipe it and give it to a thrift store. Maybe if you're extra nice you can put a stripped down distro on it. Really your call. But someone in your area could use it, for sure.