Extruding a (wall?) in Fusion 360? I have a model that has walls with a volume of 0.00mm that I want to extrude so I can 3D Print it. 

I was unable to convert it into a normal body in order to extrude it. 

In addition I was unable to figure out what kind of body type this is, here a picture.

And here a Picture of the Model.

How can I extrude these walls?
I think the command you're looking for is "Thicken". Recent versions of Fusion360 have moved this around, but now it should appear under the Create Panel when you're in the the Model mode (see the image below for details). A detailed description and short screencast on the Autodesk website here.