RJ45 Wall Jacks & Ethernet Ports

Got some networking cables run through the house, but instead of actual outlets, I'm just staring at these plastic covers (image 1).

Once you pop the cover off, it looks like image 2.

Any idea how I actually get this thing up and running?

Is it like this everywhere you look for an influencer? Honestly, do you even know where that cable goes? What we’ve got here is just a coupler... basically just a long-ass extension cord.