Why is login so screwed up?

From: Chuck Mendell (dnegorsk@tampabay.rr.com)
Date: 12/13/02

From: "Chuck Mendell" <dnegorsk@tampabay.rr.com>
Date: Fri, 13 Dec 2002 22:06:51 GMT

I'm new to Linux. Have Red Hat 8.0 Personal. Trying and willing to learn.
When I set Linux up, I gave them the root password they asked for. I also
gave them a user name for myself and a password for that (different than
root). I wrote them both down so I wouldn't make any errors. I registered
with Red Hat and gave them a third different user name and password (They
insisted). Ok, so far so good! When I booted my machine, it asked for a
login with my user name, and it showed a long number, separated with
hyphens, for my
computer name??? I tried to login using the name I gave during setup, along
with the password. It refused me, eventually letting me login anyhow. It
said it couldn't locate me on the internet. What is going on? I just want
to simply login using either my root and PW or user name and PW, and I
definitely want to change that very long computer name to something shorter,
because it appears as part of my prompt when using Terminal. Can anyone help
me or direct me where I can get help?