I find myself needing to supply two devices with wired internet. I had thought my Vonage box was a router than contained more than one “out” ports for ethernet cables, but I now realize it only has one(cheap thing they gave me).
Anyway, I do have a somewhat older, but working wireless router that I don’t use. It has multiple “out” ports for the ethernet cables.
It may also be worth checking to see if your wired modem has a USB-out as well, usually you will find on the standard modems supplied by ISPs that there is an ethernet port and a USB port so you can have two machines connected to it.