Im sure this is explained somewhere but I have been looking all over the place on the web and they are all for previous versions of ae which are confusing the hell out of me....
how do I get, lets say 3d text i made from c4d into ae?
You can't import objects(meshes) themselves. And why would you? You can render a multipass using object buffers which isoclate the data so as to appear to AE as being in 3D space. From there you can edit almost everything except the mesh itself. Fog can be placed around the object, depth mapping, ect.
//Here's a pretty old example but it worked for me using 6.0