If you are going to learn to make Poser content learning 3D modeling per se is going to take you 10 to 20 times as much time as anything else. Spending all that time limiting yourself to Poser seem shortsighted IMO. Perhaps you should start with a program that have a good renderer.

Only 4 program have the GoZ button that integrate ZBrush. Max, Maya, Cinema 4D and Modo. Without zBrush you are forever doomed to be a hobbyist. Even if you start out with no ambition at all it would be unsmart not to have all options open. You never know what will happen.