hi ,
first you can start with the base meshes in the content library (preset/sculpting/base meshes ) and modify them , add details ..etc
this tut will give you a good understanding how things work :
this is a sculpting video in c4d , not how to use the tools , but it is very helpful :
I highly recommend right click on any sculpting tool and show help , you will see a lot of helpful information .
after you learn the tools of sculpting in c4d , you can watch blender tuts about sculpting , you can follow most of them in c4d (the tools is little bit deferent , but if you learned how to use the sculpting tools in c4d , you can follow them very easy ).