Does anyone know any free creators for animals and people that are easy to learn as in 2-3 weeks.
Assuming you’ve got some artistic talent and you’re willing to put serious effort into learning the tool, Blender is free and can do anything you need. I would recommend buying “the Essential Blender” as a printed reference, although there are a couple of very good video tutorial sites. (Aside from some illegible diagrams, “the Essential Blender” is an excellent book, with clearly written tutorials followed by discussion chapters that flesh out your understanding of the concept discussed.)
If you want a program that will do most of the work for you, expect to pay.
If you want a program that’s easy to use with a slick interface, expect to pay.
There is Makehuman (a free Poser-like program). You might give it a shot:
http://www.makehuman.org/blog/index.php
That said, Blender is remarkably good for open source software. Its UI is arcane, but so is XSI’s or Lightwave’s. And Blender has a seamless workflow to Unity.