I think an absolutely great use for an old server at a youth center would be whatever the kids decide to use it for. Seriously, put it to a vote. There are lots of fun options, like a Minecraft server, one of the various Discord alternatives, a private wiki, or whatever else you find on the Awesome Selfhosted List . Just let it be their choice.

And, more importantly, set it up with them. Let anyone who wants to be involved in the process join in. If you’re kind of a newbie to Linux yourself, that’s even better; let them see you fuck up. Let them help you search for answers when you run into problems. Make it into a collaborative project.

Now, as for the actual hardware you have there… Man, that thing is ancient. If it’s what you’ve got it’s what you’ve got. As I’ve already indicated I think the process is worth more than the result here. That said, if you look around you can almost certainly find a refurbished old corporate PC for a hundred bucks or so that will be more powerful. Liquidation auctions are especially good for that kind of thing.

Firefox with ublock origin for desktop and mobile. Grayjay for mobile (integrates Nebula too so you can get both your feeds at once). Android TV with FCast and Smart Tube Next for your TV. Never see ads again.