Welcome to linux! It's quite a bit different from windows, so don't get discouraged when things don't work out.
I am a bit confused as to the state of affairs concerning your computer. My understanding is that you have, at least, two optical drives in your computer, one a DVD and the other a CD.
Situation 1) The installation disk is a cd, and not a DVD, don't worry about what tray opens. Stick it in where-ever and enjoy.
Situation 2) The installation disk is a DVD, and not a CD. Your distro has your CDRom confused with your DVDrom. Perhaps your DVDrom is not in fstab, and only your CDRom is? Could you post your fstab.
Situation 3) Unknown cause for optical drive problems still exists. You can mount your windows drive. Download the sources for kppp from windows, mount tjhe windows drive from linux, and compile it. Though the optical drive problems still exist you now have an internet connection and can read Slashdot in peace.
Assuming situation 2, my guess is that you DVDRom is not in /etc/fstab (especially if you have it as a slave). You'll need to edit add it to fstab with a text editor of your choice. I use emacs.
You can read all about fstab by getting to a terminal (konsole is the program you'll want, if you're using KDE) and issue the command "man fstab". man is the program that allows we users to read the manual pages for the various apps.
This place is a great forum to ask questions. Also cruise over to www.tldp.org
for lots of HOWTOs and guides. Be sure to read http://www.catb.org/~esr/faqs/smart-questions.html
since some people can be mean.
If you really want to learn Linux, use Slackware (http://en.wikipedia.org/wiki/Slackware
). It's not as user friendly, but user friendly kind of gets in the way of real learning.
Slackware's a bit like a father through his child into the swimming pool to teach her to swim, so at first it can be a bit overwhelming. It's worth it though, you'll be surprised at how fast and how much you learn.
Hope I've helped, and again welcome to Linux. If you're out to learn linux, be prepaired to read and read and read...