Fully agree on Debian, as long as you're up for a learning curve. In terms of performance it's fine; I've run it on a machine with a 40MHz processor back in the day with no GUI and it worked fine. If your machine can do XFCE then so much the better than that. Just be aware that there's a bit of learning curve - if you're unfamiliar, just expect that there'll be some adjustment period and learning / things not working right while you figure it out stage, and expect to read documentation and have technical challenges involved.

I would also recommend if you do go this route to do small images instead of complete images. "Complete" is for if you expect to have no internet (so have to download everything you might possibly need.) Small is fine in 99% of cases. Installing from the internet is exactly as easy as installing from disk, except that you don't need to find the disk and you don't need to download a big honkin' disk image with 5% of packages you'll use and 95% which you won't ever touch. Debian is big.