Make it easy....get:

https://www.amazon.com/TRENDnet-Unmanaged-GREENnet-Forwarding-TEG-S16DG/dp/B07WD786R4/ref=sr_1_18?crid=1N0TAJ70ZM77&keywords=16+ethernet+switch&qid=1682981547&sprefix=16+ethernet+switch%2Caps%2C105&sr=8-18 (you want a 10/100/1000 unmanaged switch..not just 10/100. This is the cheapest one I found looking at Amazon and should be all you need).

plug all the ethernet cables (14) in plus the blue one.....and connect an ethernet cable between the router inside your house and the nearest coax plug in the wall. It should "magically" come to life :)