It all depends on the what you are planning to model.
If you are going to do archviz like me , you could use Archicad or Autocad Revit. Others use Sketchup.
I am using Archicad, and that is because it is like custom made for me doing mostly straight forward (Dutch) Archviz. It could have been Autocad Revit as well. It is very architectural (with libraries to make it easy by adding complete models of objects).
Cinema4D is much much better in freeforms, but not too easy to learn.. at least not for me. I did not have a click with C4D as I did have with Archicad... So finding software that suits is another issue, like a coat fits or not. (could just be me though
If I had to start from scratch and were planning to do freesculptural forms for visuals Archicad would absolutely not be the way to go.
I would advise you to look around a lot and find out where your heart belongs... ...go for demo software to find out, look around on different forums (maybe you are already
, look at youtube tutorials... and try to find people that are doing now what you want your future to be, and see what software they ar using.
If I were you I first would take a look for the open source software (lIke RIkk suggest Blender) and see if you can do your thing with that... (saves you a lot of money on long term
good luck with your yourney