Right, so, I need a little bit of guidance. I want to tank (Yay!). I played Vanilla through Cata (and sporadically through 1-2 other expansions), mostly as a Fury/Arms Warrior. I started fresh on Anvilmar as Prot Paladin. I’m level 60, I haven’t picked up Dragonflight yet, as I want to play through some of the BFA and Shadowlands content before I do. I tried to tank Freehold as a Normal PUG last night, and as it turns out, I suck (big surprise). I need to figure out where to start, because I’m totally lost. I realized I needed to research the instances first, which I didn’t do, because I never needed to before, someone was always there to teach me, so I just went in, got through trash with no problem, reached the first boss and realized I didn’t know anything about the mechanics of the fight. Long story we wiped twice and I got (rightfully) booted. I watched a few YT videos but they all kinda assume more knowledge of the game than I currently have. This may not be fore me, and I accept that, but I want to give it a shot.
step #1. Familiarize yourself with your abilities. Know what each abiltity does and how it effects your game play in game situations. Do some senario’s and PVP for this as nothing will teach you as easily as having others adapt to you to overcome you quickly as in pvp. But this is just to teach you what each ability does so you have a good understanding of when you need to use them. (This will take time, IE more then a week)
Step #2. after you have a great deal of information on what and when to use each abillity, start researching the dungeons you are wanting to do, includes reading the dungeon journal / guide in game so you know what each of the abilities the bosses do so you can know what you should do to counter those stated abilities.
Step #3. Gather some guildies to go thru the dungeons with you and let them know what it’s for upfront (Most will help you out and go with you) This will get you some actual experience in the dungeons you studied with helpful people. This will also have you listen to constructive critasim and advice to help you and apply that knowledge so you get better and better. (This will take time, IE more then a week)
Step #4. You should now be comfortably aware of the dungeons you going to do and how to adapt to them so you are now ready to pug comfortably.
Are you familiar with the M.o.p. Training Grounds?
It’s the absolute best place to test 5 man. It’s you and 4 a.i. npcs.
You get wave after wave of fights and you can practice what your talents do.
As far as actual practical advice.
Talk to
Aarril for Protection Pally
Juaq for Prot Warrior
Crazy for Guardian Druid
Jentaru for Priest Tanking
Trevain (Not a tank)
Looks like he is playing horde.
@Lorantell Me? I’m playing Alliance on Anvilmar.
@Macneel I did not know about the training grounds. That will help a bit I’m sure. Thank you.
@Arcano Step 1 I think I have down. I’m usually pretty good about that, but maybe it needs to be at level above. As for the rest, I guess I already knew that was the answer. Don’t know why I expected there might be an easier way. I guess there’s no such thing as a casual tank. 
Thanks all for the great advice.
I tried tanking once. A guildie insisted I could do it. (I was a Main Tank Pally Healer and knew my abilities and the dungeon well.) I sucked. A PUG who joined us said I was the worst tank ever. I agreed and never tried again.
So you? You got this! You already understand what you need to do. And that is half the battle. The rest is practice and details.
My best advice as someone who royally sucked, but knew what tanks were doing? Be aware of your players as well as the boss, adds, etc. The best tanks I knew were peeps who did that. They knew where every player was and what they were doing. I don’t know how they did that. But I’m sure our awesome tanks can fill you in on these nuances once you get basics down. But they know when to taunt, who was out of place, who was floundering (as DPS it’s almost always me.)
Welcome and best of luck! I’ll run dungeons if I’m available and you don’t mind me mostly dead. (Getting old sucks. I used to be really good.) 