I'm on a different server, but maybe I'll start you with some tips. Pvp has a learning curve. It's not for everyone, but give it some practice before you assess. As an imperial DK you're going to be a tanky thug, lol. Your strength will be your survivability. Your weakness is lower damage.

To start, you mention wanting to level assault and support. These level entirely based on AP gains, so let's first go over some tips there.

- once per hour, go into a delve and kill a named boss. This puts a 1 hour Blessing of War buff on your character sheet (check after killing). This offers 20% extra AP...helpful!

- keep captures start at 6,000 base AP. The bigger the battle, the more that ends up in the pool. You need to be on property when the keep flips color. The property line is usually designated by a moat, cliff, wall...about halfway to the resources.

- resource captures offer 1,500 base AP. As with keeps, you need to be on property.

- kills offer ~500-2000 AP, with that split between the people earning the kill.

- defenses earn AP that flows into a "bucket" that is distributed to everyone on property 1-5 minutes after a battle ends. IMPORTANT: a lot of people don't understand how this works. You're...um, blue. Ok, so let's say you're at a blue resource and five reds approach. They get slaughtered on property. That's about 10,000 AP into the bucket that will be divided amongst everyone on property when the system finishes calculating it. If you stay on property, you get a share. If you run off, you do not. This is more important in big battles...sometimes it takes 10 minutes to release the bucket if a battle went on for an hour. Stay until you get the tick. The other night I got 25k ap because we had a huge resource battle, but my team ran off before the tick came in...so I got their share.

- wall / door repairs. These earn 60-80 ap each. For new players wanting to level their skills, don't overlook repairs. You can buy either with gold, so this is one way to convert gold into AP. Almost any keep...especially the ones that flip a lot...will have walls that need repairs. On some of my toons, when I want to level I grab my blessing of war then go make 5,000-10,000 ap repairing things. It's boring, but effective.


Newbie tip - be in a group

groups are your friend. You're handicapped because you're low CP, and your dps is already going to be low. You don't have to Zerg, but try to join a decent group. Put out a text chat, and feel free to say you're a newbie stam DK. There are great groups in Cyrodiil, and there are horrible groups. A good group will have friendly players chatting and willing to help out answering questions. In a couple of hours in a good group you'll learn tons about every aspect of the game.

Another group potential for your toon is (I'm sorry) as bait, lol. A lot of people play the "resource farm" game. In this strategy, a small group goes into enemy territory, takes a resource then waits to kill anyone who comes to recapture it. I play a stamblade and do this all the time with my stamblade friend. When three reds come to take back their farm, my friend and I slaughter them...that's 6,000 AP for the kill, then 6,000 in the defense bucket. We would LOVE to have a DK tank on property to distract, tank, root, etc while we pick off enemies one by one. Practice tanking a little, then maybe put out a zone chat "DK tank looking for some dps to run a resource farm with". Get a stamblade, mag sorc or magplar to murder with you and you're golden.


Gear

Gear is always key in ESO, and pvp is no exception. Many players use a pvp-specific gear set. I absolutely do. One main reason is that crit damage is INSANE in pvp right now. To survive, a lot of players wear impenetrable gear. My gank bow build will snipe an unprotected player for 16k...you're really off to a bad start if that's the first hitmyou take in a battle. Players who use protective gear only get hit for like 7k...it's hugely helpful.

And Sometimes you might want to mix up armor weights. And of course, you might want a set that is specific to pvp, like marksman for bow builds or vicious death for mag bombers.


Set / build

I am not a DK expert, so I will simply refer you to one of my favorite theorycrafter's site: alcasthq.com. His DK pvp builds probably offer some really great tips. He also covers CP allotment for people under the cap, which is helpful.



Once you're good to go, get in there and start fighting! Whether you group or try solo, try to follow your team a bit. Battles go in waves.D.C. Will push down past ash or east to chalman. When your team is pushing, go help take the next keep. When an enemy keep is flagged, check if your team is taking it. If you see multiple blue siege on it, get there fast! Get on property and help secure it, making sure you've crossed the boundary when it flips.

Once your team is overextended, the others will push back. Help defend your keeps from the walls. There's an art to getting kills this way...it takes practice. Try to get hits in on enemies, and try to focus on outliers rather than the core of the Zerg. It's easy to kill the guy who wanders 500 meters to the left of his team than it is to kill in the Zerg. If you defend successfully, wait for the tick. If you die...cie la vie. Respawn at the next keep back and prep for another defense.