Help me make this Windos PC slightly less awful (opens in new tab)

So I bought a pc for £60 I am aware it is ancient technology but I liked the case and it has some nice fans and things, I want to make it slightly less terrible (I’m literally only going to be playing beam ng drive on it) so any suggestions on what I can swap out on a very tight budget to make it somewhat useable I am willing to buy second hand (in uk)