Yes, Susan, as Peter indicated, there are a lot of details with that machine where you can go astray.
Let's clear up the selection of destination first as it seems to trip up almost everyone.
There are two dials; one will select the general location and the second will select a particular room at that location. Then you must push a button on one of the knobs (the right one, I think). If you've done it all right, a red display will appear on the screen.
After selecting a location, you must adjust the 4-lines to the target on the central viewing screen.
Hope this helps.