The pinch-to-zoom function on trackpads (and ctrl/cmd+scroll) changes the field of view of the camera, rather than moving the camera. The scroll wheel on a mouse (and scrolling on a trackpad) physically moves the camera 'backwards' (depending on camera orientation) and keeps the FoV fixed.
Using CTRL+F (CMD+F on Mac) will focus the active camera viewport on the selected items, but if you are just using a trackpad then you might find you can't zoom in (reduce FoV) far enough to be useful.
You can adjust the measurement scale post import, but it sometimes won't behave correctly, and you should leave it in the scale the model was originally created in, otherwise any lights/projectors and other imported objects will not be in the same scale.