My advice would be to do a Stamden Orc. I would picks a more tanky race for a DK so you can switch between dps and tanking as you go along. Orc is ok for tanking, so not a terrible choice if you go that way.
Tanky due to increased healing via major mending passives
Very "in your face, batter them down" Warrior playstyle, lower mobility
Quite survivable in PvP if you know how to maintain your buffs and keep your vigor/heals up.
On the other hand: Can get caught easily open-world due to lower mobility compared to other classes.
Pulls very good DPS in PvE with molten whip morph increasing all ardent flame abilities' damage. Has an easy static (generally use the same skills in order all the time) rotation in PvE.
One of the OG classes, very fun to level up but can take some getting used to in regards to PvP. When mastered, however, Stamina DKs are very formidable.
Relies on burst damage (high damage in a short time) via subterranean assault
Very buff-heavy class, not as many "damage" or "combat" skills on your bar in PvP.
Very good in group play PvP.
Ideal PvE DPS set-up has the Bear companion ultimate (uses a pet).
PvE DPS can be more dynamic as you are focused on constantly using your subterranean assault skill (generally using sub assault between 2 spammables, 1 buff 1 spammable, 1 ultimate 1 spammable/buff, etc.)
Class was introduced in the Morrowind expansion. A very powerful class with a very different feel compared to other classes.
Your choice of Orc is great as it is the BiS for Stamina PvE DPS at the moment and is one of the top races for Stamina in PvP due to increased sprint speed and weapon damage.
I personally main Warden because I love the Nature aesthetic in MMOs, but I played Dragonknight for a long time before and can attest that both classes are really great, but it's up for you to decide which playstyle you like better.
I'll say that learning how to survive with Dragonknight makes you a better player because it helps you survive with all of the other classes. I think it's a really respectable class and it's in a good spot right now.
Wardens as I mentioned before rely a lot on buffs for PvE, which means that if you are not keeping an eye out you can get caught with your pants down and die really fast. Sub assault is also very easy to dodge in 1v1 situations, but the group utility is brings is one of the best in the game.