Get a 5 port ethernet switch. Plug in the line from the router and then you can plug in up to 4 other connections for computers, printers or other devices that need a wired connection.

Example:
https://www.amazon.com/TP-Link-Ethernet-Optimization-Unmanaged-TL-SG1005D/dp/B000N99BBC/ref=sxin_2_ac_d_pm?ac_md=1-0-VW5kZXIgJDE1-ac_d_pm&crid=3UFI1TYRM46SX&cv_ct_cx=5+port+ethernet+switch&keywords=5+port+ethernet+switch&pd_rd_i=B000N99BBC&pd_rd_r=06b74717-c0d5-4c8f-9e38-7faa9cce6d82&pd_rd_w=vg0qj&pd_rd_wg=HUdm6&pf_rd_p=0e223c60-bcf8-4663-98f3-da892fbd4372&pf_rd_r=YZ1A59TE0V5CWS4476EJ&psc=1&qid=1581082780&sprefix=5+port+eth%2Caps%2C237&sr=1-1-22d05c05-1231-4126-b7c4-3e7a9c0027d0