You have a variety of different viewing options in Inoreader.
You use the left sidebar (which you can lock and unlock with the hamburger menu button at the top of the sidebar) to navigate your tags, folders, and other content options. When you click on a folder title, you will see to the right all the contents of that folder. When you pop open a folder, you can click and view individual feeds in that folder.
Rather than trying to document all the different ways of exploring content in Inoreader (there are probably lots of ways I've never even tried myself), I would urge you to spend some time exploring and see what you think.
Also, as I mentioned earlier, there is a mobile app version of Inoreader also, and like the browser-based version, it offers a variety of viewing options.
And now that you've got the basics of subscribing to feeds and reading the content of those feeds at Inoreader, I want to circle back around and say something more about subscribing to RSS feeds without relying on Inoreader's auto-detection: Blogger RSS for Comments and Labels (and WordPress feeds too).