1) I assume since you've played MUDs before, you are familiar with the concept of lag. Lag plays a vital part in all PvP encounters (either from lagging yourself with a command or getting lagged by another character's command). Ask a bunch of questions on the newbie chat about lag if you want to get a better handle on it.

2) It's called CarrionFields for a reason. You will die. You will die horribly. You will also probably get looted. These are inevitable things. Best to get used to them and learn how to deal with defeat and re-gearing (it's probably THE most important skill in CF).

3) Role command is your friend. Think up a cool story for your character, write it down. Now Immortals will understand what your character is all about and occasionally they will act on that. You had a relative who was a priest of Rayihn who molested you and that's why you hate all Rayihn priests? If it's in your role, odds are either Rayihn or someone like Enlilth will act on it.

4) Gear is important, but not the end-all-be-all. See the 2) above, and realize that while having good gear is important, being able to kill someone without it is WAY more important.

5) Decide if you want to focus on PK or RP. Of course, the goal is to do both, but as someone starting off you should focus on one of the two if you can. I focused on RP with my first character then worked on my PK with several successive characters (for example).

6) As a newbie, pick a survival-able class as your first character. Assassin/Ranger/Bard are great choices for this. Plus, if you roll up a bard, people will want to group with you (because bards are a great member of a group). Grouping with people is important as a newbie because A) you'll learn areas just watching other people lead the group and learn where to rank/gather gear/etc. Also, grouping will give you allies that potentially will help you survive/kill people.

7) Type where a lot Like, A LOT. It's crucial to know when and where you might get attacked.

7A) If you do not start a fight, don't continue it. Always strive to control the when/why/where of a battle if you can. Eventually, you'll be able to stay in fights you didn't start, but for now concentrate on only fighting battles you control/start.

8) Accept the fact that your first character is going to be a learning experience and try to con-die him. I con-died my first character and I can't tell you how important that was to my evolution as a CF player.

9) Ask questions.

Good luck.