Help Upgrade a 15-Year-Old PC for a Special Gift

Hello Internet! I've never had money; I'm paycheck to paycheck, and I don't really get my partner Christmas or birthday gifts, as crappy as that sounds. They never have had money either, and we just don't get or give gifts. It's really unfortunate.

This past Christmas, I felt so bad. My partner has an older PC (about 15 years old), and I've always enjoyed playing games with them. I've been gifted some newer games from relatives, and sadly, my partner cannot run them. I really want to do something special for them. I built a small handful of parts that would upgrade their PC to a decent spot. I'll even share the PC part picker. I'm really just hoping to get the parts for them and surprise them. Please help me? :)

https://pcpartpicker.com/list/DPbrv4 <- parts