I'm using Photoshop CS6 to make a label and I need to convert all layers to InDesign CS4. I've never done this...is it possible?
It can not be done.
There is no direct method for converting a Photoshop File to an InDesign file.
You can create a new InDesign document and place (link to) the Photoshop file. But other than that you must recreate the file in InDesign.