If your system has been set up for reading Usenet news, getting started with Gnus is easy—just type M-x gnus.
On starting up, Gnus reads your news initialization file: a file named .newsrc in your home directory which lists your Usenet newsgroups and subscriptions (this file is not unique to Gnus; it is used by many other newsreader programs). It then tries to contact the system's default news server, which is typically specified by the NNTPSERVER environment variable.
If your system does not have a default news server, or if you wish
to use Gnus for reading email, then before invoking M-x gnus you
need to tell Gnus where to get news and/or mail. To do this,
customize the variables
See Finding the News.
Once Gnus has started up, it displays the group buffer. By default, the group buffer shows only a small number of subscribed groups. Groups with other statuses—unsubscribed, killed, or zombie—are hidden. The first time you start Gnus, any group to which you are not subscribed is made into a killed group; any group that subsequently appears on the news server becomes a zombie group.
To proceed, you must select a group in the group buffer to open the summary buffer for that group; then, select an article in the summary buffer to view its article buffer in a separate window. The following sections explain how to use the group and summary buffers to do this.
To quit Gnus, type q in the group buffer. This automatically records your group statuses in the files .newsrc and .newsrc.eld, so that they take effect in subsequent Gnus sessions.