I have Toshiba satellite M 70. I want to use kubuntu live CD, downloading it. I want to know some things,

1- Can I use internet with dial up via modem of my noyebook on this live CD( before I tried puppy linux live CD but it did not recogvize my modem and I was not able to use internet). This is my main issue.
2- Can I work with work documents on it.
3- Is it easy to use. I never used linux except for the trial I mentioned above. I don,t know commands like DOS.
4- What about the security issue. I mean being a live CD, I can,t install any antivirus or firewall. Does these CDs have Antivirus software as well( seems a rather silly question!)