janiani I'm not understanding what the problem is. Since you have a non-Roku TV, I assume you have one of the Roku players connected to your TV. Do you have the Roku remote, or are you trying to use the Roku app on a phone as the remote? If you don't have a Roku remote, there's no way to connect your Roku to a wireless network without one. If you have a Roku Stick player, you MUST have an official Roku remote, as they do not support using a simple IR remote. You cannot use the Roku app to control a Roku unless the Roku and phone are both connected to the same private network, and there's no security setting in the WiFi that blocks devices from seeing each other.
FYI: IP addresses are assigned by a device on the network (called a DHCP server, usually part of the network router hardware), and it will not be the same number on different networks (unless by some sheer coincidence).