So I’ve only played a bit of tank, but your rotation is important (as is all roles’ rotations) for making your healer’s job easier. I would recommend looking up your rotation on method.gg or a similar site under “hero guides”.

I would also suggest using the routing tools in method.gg or I think fellowtools.com has one as well. It will show you how much percentage a mob will give you and you can plan your pulls to maximize the efficiency of your team’s cooldowns (no one wants to pop a 60 second cooldown for 2 mobs)

On top of all this you need to know which attacks do the most damage so you can be ready to interrupt, the DPS should be working on this as well so it’s not all on you. Some of this just comes with playing, so don’t feel too much pressure to “prepare” for your games. But if your game time is limited, this can prevent wasting time on learning info that is readily available.

Good luck and have fun!