Router with SIM Card Slot

Hello,

I live in the country and don't have many internet options. My prior router took a sim card, so I need a new router that does the same. However, I am not familiar enough with routers to be able to determine which uses a sim card as opposed to ethernet.  It needs to be a high speed with a wide range to reach throughout a two story house with many devices connected. If I purchase a Netgear Nighthawk R7800, will I need to purchase a modem or does it have a sim slot? If I do need to purchase a modem, am I able to use my SIM card in a Netgear modem? Any help appreciated.