Scared to start any level 50 stuff.....any suggestions where to start?

[DMooseJ]

I'd suggest getting started on your relic weapon ASAP, running Amdapor Keep (It's been nerfed pretty hard by now, also need it for a step on your relic line) and most importantly, unlocking CT. You can jump in CT in AR gear pretty much and with the weekly limit lifted, you'll be swimming in myth and iLvl 80 left side gear in no time.

As I started as a tank, I typically felt the same way you did when trying out new dungeons especially since, as a tank, I'd hate not to know what I'm doing. I typically watch guides like MTQCapture's (https://www.youtube.com/user/MTQcapture) as she gives a nice simple overview of the dungeon and lets you in on most of the intricacies so you're prepped going in. The only way to really get comfortable running these dungeons is by running them a few times, experience is the best teacher even if you fail once or twice.