The CMS has a lot of capability but you really have to play with it. On my site I have 5 sections with 4 of them showing on the home page. I have about 400 categories. When one of my staff writers writes about a group of football players they select category that corresponds to their name. My section is Football and categories is the number of the player it is about. I then have an widget with 3 tabs where users can select what sport they want to read about and on the players profile I have a stream that shows the latest news about them.
My point being is you really need to decide how you want to organize your content and how it will grow. It makes it a lot easier to set it up right at first rather than going back and change a bunch of sections and categories. HM666 answered your questions spot on but feel free to ask any more. Here is my CMS so let me know if you have any questions on how I did things.
https://www.canesinsight.com