Each camera must have an ip address assigned , routers do this two ways , in basic terms automatic(dhcp) or fixed(static)
As said above give each camera an ip address static then as other post also says try and enter the ip address for each camera into your internet browser and see if you can access it , this way you know its working in house
Try doing one at a time, if you don't know how to make it static meaning the ip, it will have a automatic ip assigned somewhere which you could see in the router
You get me? Or them?