With the fiber it comes into your house and then has a box called an Optical Network Terminal, that it terminates in and then that converts the signal and your Router/Modem plugs into that via an ethernet cable. The router will have several ethernet ports that you can plug cables into for devices or will have WiFi for you to log into. I suggest you do a search and start reading up on ONTs. This thread should help. So many ways to do this.
https://troypointinsider.com/t/verizon-ont-adding-ethernet-port/75834