Hello Dawn Schulz,
You are correct you might need to run either Coax or a Phone line, most of the time a house will have multiple locations where you can hook up a cable tv box or phone, if you have any of these nearby the middle of the house you may be able to simply move your equipment.
If your computer is hard wired then your best bet would be a mesh solution, while keeping your computer plugged into the primary Mesh device that acts as a router.