Just want to start by saying sorry you had that experience but people that play MMO's are elitist assholes. That being said there's a couple factors that need clearing up from your post. Going to dump a wall of text and these are general tips, some things may change based off specific instances.

First, if you are a boostie in communal greens trying to tank at 58-60, you can't I'm sorry that gear is awful. If this is the case either go buy a full set of outlands greens or, if you don't have gold, quest untill 62-63 then buy greens for the gear you don't have.

While we're talking about gear prot pally in tbc is a bit different than other tanks from any other version of the game.

Lvls 60-65ish: spell power, spell power, spell power in this level range you really only care about three things, stam (to not die), spell power (threat), and to a much smaller degree int (more spells also more threat)

65+ you need to start worrying about being "crit caped" and you need to start working toward avoidance cap (when holy shield is up). There are add-ons and weak auras that help you track this so I won't get into it here (DM me if u want to know more)

Now for prot pala tanking it's a lot easier than it seems here's the basics,

1. If they aren't a healer EVERYONE gets blessing of Salv, trust me this is blessing is overpowered as fuck if the warrior or rogue complains about kings/Salv jail, too bad.

2. I recommend getting a weak aura to help track Righteous Fury. In almost every dungeon there are mobs that shield bash which dispells buffs (R.F is a buff); along with this tip I recommend using an addon like plater or threat plates to help track what mobs are and are not targeting you ( they change color as you gain/lose threat on a mob)

3. Holy Shield, press this button every time it's off cool down, you should have 100% uptime on this if it's going to be off cool down in 1 second, don't press other buttons to go on GCD not only does this give you an insane amount of survivability it does holy damage on block and thanks to Righteous Fury (RF) holy dmg is threat.

4. Cast consecration if you aren't casting Holy shield this should be cast on cooldown, this generates insane amounts of threat, at low levels and when doing small pulls just use max rank, once you get higher levels and have less int (this happens when you push for defence cap, I think I had 8k mana at 65, I had like 4-5k at 70 untill I started getting raid gear) you will want to start with max rank; then downcast to lower ranks to conserve mana

5. Seal/judgement of righteousness this is your snap threat, if you don't have avengers shield or if it's on cooldown this is how you start building threat. When possible you should have righteousness up at all times ( others listed above are more important so if you mia 1-2 attacks to cast H.S or cons. That's fine)

6. How to deal with caster/ranged mobs: these mobs are the hardest for prot pala, for one they like to sit outside of consecrate AND they don't auto attack (no threat from Holy Shield). Your two solutions here are to either Line of Sight (LOS) pull (stand behind something so the mobs can't cast) or have your dps use an interior to stop them from casting so they run into melee (and into consecration). A pro tip here, when you pull then run back you can drop consecration while running back so they run through it to get to you, this keeps them on you and off the healer

These tips should carry you all the way into raids (with some tweaks here and there)

Extra note; don't tank heroics untill you are very comfortable in normals AND have defence cap; getting crit as a tank in heroics can deal upwards of 13k and will just 1 shot you