Honestly, you're still at the level where the best thing to do (in my opinion) is just level up and try out all the new stuff you come across. Get as many skill lines unlocked as you can, see how different abilities work, experiment with different gear set bonuses, that sort of thing. The only thing I would advise doing for sure is having some sort of self heal ability equipped, and queue for any dungeons you do as a DPS (so you don't have to build a specific way and you get to keep the freedom of trying stuff out without worrying how good it is).

Once you reach max rank (champion 160) would be the more appropriate time to think about making a build. It sounds like you want to be a PVE tank (an excellent choice if I say so myself), so here are the things you really kind of need to set yourself up, once you get to c160:

- Some sort of taunt
- Some sort of AOE damaging ability
- Some sort of self-heal
- At least 32,000 armor

A taunt is what makes a tank a tank. I mean, if you don't taunt to grab aggro you're not really tanking, you're just a really thick damage dealer. Often, tanks will grab a secondary taunt for backup (for example, I like to have one taunt equipped that doesn't take many resources to use, and another taunt I can use at range), but you need to have at least one.

An Area-of-Effect ability isn't strictly necessary, but it allows you to easily grab the aggro from a crowd of mobs all at once at the beginning of a fight, so long as no one else has aggroed the mobs yet. This allows you to group up the mobs so that your damage dealers can easily kill them all in one place, instead of taking each one out individually.

Some sort of self-heal, usually a strong one, is important. Sometimes your healer won't be there, and often they're busy taking care of the less-than-smart damage dealers, so it's important you can keep yourself alive without help from others.

The damage reduction from armor, in PVE, caps out a bit beyond 32k spell resistance and 32k physical resistance (aka 32k armor). So if you don't have at least 32k, your defense is weaker than it could be, and if it's over 33k, you're wasting points on armor when you could be putting those points into something else. If you use abilities to get yourself up to 32k, you do not need to passively have that amount of armor either - as long as you have 32k armor with your rotation of abilities active, you're all good.

After that, there are things tanks often have, but aren't strictly necessary. These usually depend on the build or player tastes:

- Crowd control
- Movement
- Team support
- Additional damage reduction
- High health

Abilities to control crowds of enemies, or even lock single enemies into place, can be useful for controlling the battlefield, which is the tank's domain. These are especially important in PVP too, if you choose to do that. Just be aware that there is a cooldown on opponents getting stunned - after getting stunned, they cannot be stunned again until a short time has passed - that way players do not get locked in place indefinitely.

Movement abilities are fun and can really help, as many tanks are not terribly mobile. Especially if you are not running a ranged taunt, it is important to be able to get within taunt range as needed. There are also some ways to move enemies instead of yourself. These can be useful for grouping enemies up (or keeping pesky PVPers from running away).

Usually when running high level PVE content, it is expected of tanks to have some abilities equipped that buff your allies or debuff enemies. This allows healers to have more heals and damage dealers to do more damage, instead of them having to slot their own buff and debuff abilities.

There are extra ways to reduce damage beyond armor. It usually isn't strictly necessary, as there are soft caps to worry about when stacking too much, but a little extra protection never hurt anyone. If running into PVP, for example, it might be useful to put a few points into crit resistance, even though that doesn't really do anything in PVE.

Lastly, it's important to have decent health as a tank, as otherwise you can get one-shot. A good tank can technically be lower HP, but generally it's recommended to hit at least 30k health. I personally tend to run tanks that have at least 50k health after food buffs.

But again - right now, just focus on leveling up and trying stuff out. Once you spec into tanking, your damage will go down and content will take longer too, so it'll be slower to level up. So save tanking for once you reach max (the max level armor, anyway).

I should also quickly mention equipment - leveling up, just equip whatever the best gear you find is. If you get some crafted training gear, even better. Once you hit c160, get a nice set of crafted gear. This should be plenty powerful to take on most content in the game, and you should be able to use that gear to farm out for the very best gear you want for your final build.

Anyway, I think that answers your questions (to my best ability anyway). Hope I helped!

I 100% agree with @Marginis. I'll add the following:

When you are leveling up your tank skills, do it as a damage dealer. It would take forever as a tank. I prefer to do that in a daily random normal dungeon. I typically put all my damage abilities on the front bar that I use, then put 3-5 skills I want to level on my back bar. When the last boss of the dungeon gets to 15%, I finish the dungeon on the back bar and scoop up the massive XP drop. I do that until the skills get the point I feel comfortable tanking a dungeon myself.

DK is probably the best class for tanks. Lots of options out there for skills. The basic 5: Green Dragon Blood, Pierce Armor, Low Slash, Unrelenting Grip, Inner Fire. Aggressive Warhorn is also a staple ultimate. Beyond that, you can mix and match for what you need and what the group needs. Plus, it has the ability to expand when you get more experienced, for instance, a Z'en tank can help a group's damage tremendously and the DK is the best class to use Z'en with.

Whatever you are doing now, make sure you are wearing at least one piece of light, medium, and heavy so you can level the Undaunted passive.

Other than these, when you are running a dungeon as a DD, pay attention to mechanics and where the tank pulls the bosses (if the tank is decent). Interrupts, heavy attacks, avoidable one-shots, etc. That is the best way to learn mechanics for when you eventually tank.

Good luck! Tanking is fun!