You might be able to just import the DWG as a sketch (not really a Schematics design with data) that you can look at.
To get a real design in Creo Schematics, you will need to create a library of components and connect them with fibers (their term for wires) so that the data ability gives you something more useful than a picture.
It might be possible (we don't have AutoCAD) to bring in your DWG as a sketch on one layer and use that to place components and the wires in another.
My guess is that it will be easier to use a printed image to redraw the designs that you need to work with in Schematics and keep the ones that will not need to migrate in a viewable form.