Confusion regarding specific conductivity
Let's take a wire inside cable for example. That wire's conductance is just the inverse of the resistance this cable is making when electricity passes through it. This depends on things like the length, what is made of, the maximum/minimum width of certain areas of the wire, etc.

On the other hand, the conductivity of that wire is a direct property of the material it's made of. If the wire is made of copper for example, it'll have (at the same temperature) the same conductivity as any copper wire in the world (because they are all made of copper), but not the same conductance (because they are not physically equal)

I hope this helps, I'm sorry if I was wrong!