I don't tank so take this with a grain of salt, I'm just relaying my second-hand knowledge. First, between the two heavy armor skill morphs I'd probably use Unstoppable Brute as a new tank because the cost reduction of the skill will help you manage resources. Then as you progress to content where enemies hit harder you can consider swapping to Immovable or using another skill as you will have learned how to keep your resources up by then.

Second, and in a similar vein, monster sets that give resources help early on when learning, with the main one that comes to mind being Engine Guardian. Then as you get more advanced and wear sets that support the group more, the other main one I know of is Encratis's Behemoth, though there are others that are helpful as well, and bear in mind Encratis is only helpful for Mag-based groups.

Also, I know that many people who mainly play as tanks swear by the Tank Club (https://thetankclub.com/), so I'd also recommend to check that out if you haven't already

I use Tremorscale, which deals decent damage and shows you when you are effectively taunting.

For sets (what u are not asking, anyway...) Ebon and Knightmare in formed groups (with a good healer), Plague and Gloom Graced in PUG situations, where self sustain may be paramount.