How can I revive my old computer?

I want to do this as a sort of side project. So even if I need to buy new parts or something I’d want to for the sake of learning about replacing parts and not worrying about messing up because it’s an old computer.

This was my first desktop computer dating back to 2004. I don’t have the specs because the computer runs so slow that it’s so difficult to load anything in File Explorer.

But it’s:
Dell Dimension 8300 (Model #: DHM)
Pentium 4
Windows XP Home Edition

When I went to college and got a laptop, my mother inherited my old computer. And of course, no offense but, when a boomer starts using a computer then things kind of go downhill from there in terms of maintaining the computer. She downloaded so many things and hardly checked the system and it eventually became super slow.

It used to not even load Windows, but with some patience I managed to revive it to the point where I can actually start it up and look around My Documents. But there are many issues I need help with:

1. How can I fix the keyboard and mouse ports? They don’t respond at all. Doesn’t matter which keyboard or mouse I plug in, they don’t respond.

2. How can I fix the USB ports? Only one USB port responds and I use a wireless mouse with that port. It’s the port in the front underneath this hatch you have to open. All other USB ports don’t respond.

4. How can I make it go faster? I was hoping to get what my mom needs from the private documents by moving them to a flash drive and then reimaging the entire computer. But I can’t do that because it’s so damn slow at loading windows in File Explorer and the window ends up “Not Responding”. I’ve already disabled all the unnecessary startup programs to get it to load, but now the issue is loading everything else I click on.

5. How can I make the fan quieter? The fan is so loud. It sounds like it’s really pushing to keep itself going. The longer you have it on, the louder it gradually becomes, until it reaches a certain point where it doesn’t get any louder.