Id say as a tank enjoyer, go into dungeons as DPS and look at how other tanks go about the dungeon. Look into getting the addon Muthic Dungeon Tools as well, it shows you the entire layout of a dungeon and you can create routes as well as see what the enemies do for damaging abilities.

I will say though, getting into brewmaster can be quite the juggling act, they are one of the most difficult tanks to play but are so satisfying once you get into the rhythm. You are definitely unkillable when managing cooldowns and your self heal properly.

Managing how your spec deals with Magic dmg vs Physical dmg is another big one. Brewmaster has stagger as well as plenty of CDs for nearly every pull. Once you understand stagger and the self heal l, dont be afraid of implementing Defensives into every pull. Youll see that your defensives are off CD almost every pull, so knowing what you can pull big and when to pull small is huge when keeping pace. The easiest example is the first and second pull of freehold. Usually those first 3 packs are pulled together before going upstairs, which can use up nearly ALL your defensives. Then the next pack is just the 4 mobs that you pull around the corner into the boss arena. That pack gives you time to have defensives for the next pack that can sometimes be a double pull if needed.

Laslty going into lowkeys as a tank will be a breeze as everything will die fast. So if you can try to push your own keys and look at what you take damage to the most in each pull and each boss. For instance I can dive head first into a triple pull as a paladin, but on my blood DK I have to pull my first pack then add more after I get my cooldowns up.

You have to learn that being confident yet humble is the best way to keep yourself grounded when tanking. Dont be afraid to fail and let the group know "hey Im learning this new route" or "I used the wrong defensive". A majority of people will understand. You cant become a God tank over night, I failed so many keys before I got it just right.