Home network support: Setting up a network switch

I moved into a new apartment and was surprised to see that all my rooms have CAT 5 Ethernet ports in the wall. However, cue my disappoint when I try to naively plug my router and machine in two separate ports to find that the ports don't actually work. After searching various forums, I found that I have to:

1. Locate the panel where all the ethernet ports connect
2. Wire them to an ethernet switch.

I found the panel but all the wires look like this:

https://i.imgur.com/Qzm72g0.jpg

I'm not sure what I need to do from here to plugging into my network switch. Any guides or advice would be extremely helpful. I don't need every port connected to the switch, only one or two. None of these look labelled so I might have a difficult time isolating which cable runs where.

And about the network switch... Any qualms about using an old router that has the AP turned off?