Welcome to the community!
Do you have at least one Viewport on the layout? Without a Viewport, you will not see anything in Model Space.
If you have a Viewport, is it turned on? In Paper Space, select the Viewport and, on the Properties Palette, on the Design Tab, under the Misc category, check the On property - is it set to Yes? If it is set to No, select the No and then use the drop-down menu to change the value to Yes. Do you now see Model Space items?
If the Viewport was set to Yes (or, after setting to Yes), if you still do not see Model Space objects, it could be that the Viewport is looking at an empty area of Model Space. Can you double-left-click inside the Viewport to make Model Space in that Viewport active? Are you then able to run the ZOOM Extents command and then see objects in Model Space? If it zooms Paper Space to extents instead of the Model Space within the Viewport, then the Viewport is most likely locked. Unlock it and try the ZOOM Extents again.
If none of the above works for you, you may need to post the drawing as an attachment to a reply here, so that someone here can take a look at your file directly.
David Koch
AutoCAD Architecture and Revit User
Blog | LinkedIn
