When you say a budget of £500 does that include the operating system, monitor, speakers, keyboard and mouse?
As for tips:
AMD Ryzen has been well-received so in my opinion they are worthy of serious consideration and offer great value in the CPU sector.
I don't play those games so unfortunately won't be able to tell you which setup will run it at the frames wanted. Those titles are popular and I am sure dedicated forums to them will be able to better assist in suggesting specs for getting the framerate wanted.