I would mostly be doing dungeons and PvP, or exploring the map if it helps?

Pros. you get to be lazy and start at level 55.
Dont know how to play your class, still pull 20k dps.


Cons. no one really likes them

Pros:

*You start at level 55

*You can tank, this is good or bad depending on how skilled you are at the game. Tanks are in short supply making it easy to get into dungeons and secure raid spots.

*You're OP when you start out

*The class is fun and can be effective at pvp when paired with a good healer

*You do dps comparable to a DPS warrior or paladin

Cons:

*Most people assume Death Knights are noobs

*There are a lot of Death Knights, making it difficult to secure a raid spot especially if you don't tank.

*Your dungeons have a higher chance of class stacking

*People just generally seem to hate Death Knights

Experience:

*I have taken a DK to max level

*I tanked most of ICC as a DK as well as cleared most other wrath raids back when they were hard

*I did a lot of BGs and some Arena as a DK

I tanked with the class throughout wotlk, that was the only way I could secure raid spots and not be labelled a death noob, I also did some PvP, like all classes it takes practice but I found it to be very fun for pvp although reliant on healers.

My advice would be to avoid the class if you only plan to dps for dungeons, If you can handle some tanking then yeah go for it. The class is a very effective leveller and pvper if you know what you're doing.

Pros:
Easy to level
Easy to play
Good DPS

Cons:
Everyone hates them
Too many DK
Suck at tanking