It sounds like what you're trying to do is from the stone ages of the Internet!

If I understand correctly you do not already have a wifi network in your home. (Your internet is provided via some sort of cellular service/tethered to a phone or hotspot device).  If that is the case you need to go into your settings as share that connection.  When I refer to the stone ages it is because the last time I attempted to handle a setup like that was 15 plus years ago.