Try going to the panel menu and click lighting > and enable two-sided lighting. If it was off and you enable it and your model shows up, then your normals are facing the wrong way. You can also go Display > Polygons > Face normals to check if your normals are facing outward. Do a bit of googling on normals if you're still not sure.

You can also select your model and just go normals > reverse, and see if that fixes it.