I'm a nervous person with anxiety and generalised dungeon fears (!), but if you're just running small stuff and need someone to share the trauma, I can tank or heal for you. Tanking may be better, though! We're on the same server, so just look for or message/mogmail Cheeze Toastie and see if I'm available. Just offering to do this is scary for me (!), but I will do my best to get you and your friend through early dungeons so you have a chance to learn stuff at your pace with no harsh judging. You find someone else with a similar outlook for the last spot and it's good.
As for RDM, I just recently started having a look at it myself, and as with any job the best starter advice is to read those tool tips. I also used
this Reddit link here and the image it has up as a basic reference chart. You won't have all the skills on there in early dungeons, obviously, but follow the order with what you have and add them as you go. And use Scatter for 3 or more mobs as per standard AoE rules.