3D modeling is something that requires a ton patience, and can be fairly challenging to learn for the uninitiated. That said, I
DO NOT recommend Blender as a first 3D app. It may be free, but it's on a professional level and has an overly complicated interface (IMO) that likes to act evil towards new users.
If you would like to learn 3D modeling on a budget, I recommend trying Wings 3D, or 'Art of Illusion' (yes that's the app's name). Those two are what I typically use, and are much more user friendly.