Mepis or Slax. Linux has the most forgiving kernel for a newbie, so NO. Do NOT install a different kernel yet. I've literally played with OpenIndiana recently and the glory days of Solaris were ten years ago.
Actually, I don't know where you are coming from: most of the people I know who are starting fedora are just starting to realize there is more to Linux than Ubuntu. It's a little funny and pathetic to hhear Fab from Linux Outlaws (who just switched from Ubuntu) goikng through what I did in 2001 when I switchedfrom slackware. I'm back on slackware now, by the way.
MEPIS is the best Linux period:
http://www.mepis.org/
A distro based on Dabian, as Ubuntu is, it's a finely tuned and crafted piece of engineering wizardry.
An alternative is slax:
http://www.slax.org/
Which is very newbie friendly but will guide you through learning a lot.
Whatever distro you have or use check out this page:
Notice it says Unix/Linux. Try the commands: most of them should work and you will learn a lot because Linux is juust the kernel of an operating system created to run Unix programs.
If you MUST try BSD then looka this:
http://www.dragonflybsd.org
Burn it to a dvd and try it outu. USE AT YOUR OWN RISK THOUGH. To run root commands in BSD you MUST be a member of group wheel. Now ifs ands and buts. If you ain't in group wheel even root's password on't let you run its commends. That is final. There are other little gotchas.