You have installed a standalone version of Lightroom, and it won't work with the creative cloud subscription plan. You will need to uninstall that version and then download and install from the creative cloud application manager. It might be necessary for you to install an update of the creative cloud application manager. If that is the case, here is the link:
Uninstalling the version of Lightroom that isn't working will have no impact on your catalog if you have already worked on images. After you install the right version Lightroom will open the same catalog that you have been using.