If you're running Windows you've already got it. Usenet is older than the World Wide Web. Usenet, bulletin boards and Email *were* the Internet before WWW was started and as big as the Web is, Email is considered to be bigger. If the Web is anywhere now, FidoNet probably was there first.
Another term for Usenet is Newsgroups. You can go to Google and have it do a search on "groups" and it will give you some idea of what you can find. I've linked to an example search I did for another question using "MobyDick audiobook" as a search term. (1)
In Windows, Outlook Express the Email reader is also a Usenet reader. This gives you the basics for access. The only other thing you need to get started is access to Usenet, which most (but not all) ISPs provide as part of their subscription. I am given five gigabytes a month by my ISP, which they arrange to have served by GigaNews. I can purchase additional access directly from GigaNews if I wish.
Your ISP will provide you with the settings that you need to put into your "newsreader" (Outlook Express, at first) to get started. If you purchase access, whoever you buy it from will provide the settings.
To do what you want, you'll have to become more familiar with how it works and add some more powerful programs. I'll put a link below that will give you information that will bring you up to date. (2)
You'll be finding a whole new world behind the Internet world you thought you knew.