It would appear that the model from SU is displayed at a fairly small scale in LO. You are zoomed in by over 500%. As I remember it, your imported CAD file has content spread out over a large area. You can set a larger scale for the viewport assuming you have the camera set to Parallel Projection and, in this case, the Standard Top view. Do this in the SketchUp Model panel on the right side while the viewport is selected. You can also turn off the Background and set rendering to Vector which will give you crisper looking line work.
You should go through the LayOut Essentials here: https://learn.sketchup.com/