Newsgroups are part of a "system" (lack of a better word) that developed at the same time as and nominally not part of the Internet. Basically they are a collection of interconnected bulletin boards very similar to forums like this but are on servers that only house newsgroups. At the time they were evolving they were the best and cheapest and most efficient way for mostly technical professionals and computer geeks to post files, interchange data. , etc.
Binarf files are primarily pictures for hobbyists or enthusiasts. You know Trains ,porn, Planes, porn, Anime, porn, maps. porn. Did I mention there are a lot of porn binary groups.
This may work it may not, your initial set-up with your ISP very likely set up a newsreader.
Take a look at the lower left hand side of your Windows browser, next to the "Start" button, you may see an E for Explorer and an envelope.
Click on the envelope, you may get a page that shows some kind of news. xxx.xx or similar. Click on that and then go up to the File drop down and select subscribe, that may give you a very long lisst or a blank box.
Type in something you are intereted in guns, breasts, etc highlight a line that looks interesting and hit subscribe. You should see a list of messages or it may ask you how many headers to download.
Once you download double click on something on the list and see what you get.