Adding an additional Ethernet wall port

In my house I have only one ethernet port which is in my living room. I have my ISP's modem connected to it, but I'd like to add another wall port in my office on the same floor but on the opposite side of the house so I can hardwire some devices. My basement is unfinished so I was thinking about throwing a very long ethernet cable down and running it across and up through the drywall in my office. What's the best way to extend and add the new port? In my head I'm just thinking connect that long ethernet cable to the modem and ultimately to a switch in my office.

Solutions I find online talk about adding additional ethernet ports to a router or modem, but I actually want to add an ethernet wall port to a room.