Ready Made Cat Gym How Can I Connect The Two Pc On My Room?

How can i connect the two pc on my room? - ready made cat gym

I have tried my PC with 2 RJ-45 Ethernet, or on any computer that I do by hand contact with. each end of the cable are exactly the same, but still does not work. I even tried the color of some ready-to-copy cat-45 cable. Are there any other code that has been done?