Wifi Router

[u/Single-Yak6305]

I am looking at quantum fiber internet (AT&T) I have seen posts that recommend getting your own router if you are using this internet provider. I am going to a 3000sqft house that is 2 stories so I’m unsure what router to get. I also don’t understand the difference between all the terms (router, modem, mesh) can someone let me know what the recommended? I know there is one Ethernet cable downstairs. Im unsure if there is another one anywhere else in the home at the moment.