Sculpty resources for you in order of degree of difficulty-by the time you get to Blender you will need an advil.
Rokuro–A fine beginning level sculptie maker, I’ve used this to make sculpties for cushions, pillows, columns, etc.
SculptyPaint–A friend told me about this, and I haven’t quite mastered it yet even though its quite simple-again though my use of sculpties is simple-cushions, pillows, etc
Blender-I just got into Blender and I can already see that I am going to have to read the instructions, there is no open and muck about even for making cushions, pillows, etc.
All these programs are free downloads. Many tutorials are available. Enjoy!