When I open Lightroom I get a page as shown, which does not include the task bar which includes LIBRARY DEVELOP etc. All the videos I look at have an opening page including the LIBRARY task bar. Consequently I do not have access to my folders. What should I do to open the correct opening page?
Adobe has created a nightmare with their naming convention. There are now two versions of Lightroom. The version that is simply named Lightroom is Lightroom for the cloud. It is a new version that has a much different interface, and that is one that you have installed. The more familiar version is now called Lightroom Classic. It is also available for install from the Creative Cloud Application Manager. That is the one that you need to install. You are entitled to use both programs, although trying to do so especially on the same computer can become extremely confusing and it's not really a good idea. It won't hurt anything. My usual caution is just don't drive yourself crazy trying to synchronize the two on the same computer. It can be frustrating.