Selfhosted

I would never say no to using older hardware. Yeah, it'll be like punishing yourself. But you learn a shit ton.

I recently started self hosting. I started on a PC with the same specs as you've said. Booting was an issue. And tons of stuff always broke. But i learnt a lot. And then there was a time, when i genuinely thought i could do better and switched an old laptop with decent specs.

Pi's are very expensive and too dang low on supply.

So always make do with what you have. If it's your first home lab, then yeah go ahead. In a few months switch

It's a great machine to learn on. Build yourself a web server or something like that. You don't know what it can do until you push it, and you're not out anything by taking it to its limits. If it has something like a Core 2 Duo you could even run KVM and launch a virtual machine to learn about that process. Old hardware is meant to be run into the ground and you'll learn a lot in the process, including getting a feel for how much hardware you really need to perform the tasks you want. (I literally just retired a rack server this year with a Core 2 Duo and 8GB of memory, which was used to run five VM servers providing internet services.)