In After Effects, all you have to do is enable 3D for a Layer to generate 3D space. To activate 3D for that Layer, go to the right side of the Switches column and click on this box. I now have X, Y, and Z for the position of this Layer after I activated 3D.
The layer itself remains flat when you make it a 3D layer, but it gains the following properties: Position (z), Anchor Point (z), Scale (z), Orientation, X Rotation, Y Rotation, Z Rotation, and Material Options.
To make a layer 3D, utilise the Switches/Modes toggle in the timeline to see the switches, then enable the 3D Layer switch to the right of the layer. Enabling 3D on a layer gives you the ability to relocate it in 3D space, as well as material options for how it appears in the composition.
After Effects is set to use the Classic 3D Renderer by default. This allows you to place layers in 3D space, but they will still be 2D layers. All we have to do now is go down and tap OK to change this Composition to the CINEMA 4D Renderer.