Coaxial Cord Not Activated

Hi we just moved into our new home and got our first Xfinity Gateway modem, but it is not working. I have tried every coax cord I could find, around 5+ now and anytime I plug it in it just blinks orange but that’s it. I’ve downloaded the app and such and same issue. I’m curious if there is anything I can do to fix this issue myself as I don’t have a lot of funds at the moment.