I have purchased an ebook from Rakuten Kobo, downloaded ebook app on my computer, I see my book on the ebook, but cannot seem to display the book. I have tried clicking on the book, I clicked on different icons, but to no avail. How do get to see the see the ebook, so I can read it?
Have you tried using Calibre as an ebook reading app. It works well in many different environments and accepts many ebook formats. I buy lots of books in epub, from Kobo and others, and I never had any problem reading them with Calibre (though I prefer my small Kobo ebook reader).
Trying it would at least check whether there is a problem with the ebook.
Another point is that you did not tell whether your ebook has DRM (usually Adobe DRM in the case of Kobo). I am not sure whether that would require special steps to get the book displayed, but I suspect it would, at least for the first book. I cannot say more on that because I simply refuse to buy books with DRM, and have thus no experience with it.