What version of Lightroom are you using? Your reference to Books implies you are using Classic. You might accidentally be opening the cloud version of Lightroom (called Lightroom Desktop confusingly) instead. It is also possible you are not opening the correct catalog if you are actually using Classic.
Wow that is a very old version. I am surprised it still works as that is not compatible with current Macs and Windows machines. You are probably not opening the right catalog file. Select File from the file menu and look in "open recent" for your correct catalog. If you don't see anything there, use open to browse to your catalog.