Hey, welcome back to the WAR.
If you want to refresh your knowledge - or rather, get updated with the changes cuz RoR is a bit different than WAR -
check this guide made by Uchoo. Its a very good overall guide about each class and archetype.
Also i highly recommend four addons.
GuardPack - it adds a line in ur UI connecting you and your Guard (or Guardee).
Enemy - UI overhaul with a bunch of additional functions. You can disable most of them if u want, i only use the Warband UI which is beyond great, and Enemy Marks that allows you to mark players so its easier to identify known Warband Leaders and Gankers.
Buffhead - Little icons above yours and enemy's heads showing various buffs and debuffs. It can get even better with a little customization (you can ask in any major guild discord for customized settings if u want), but the regular version is great too. It shows a lot of very very important information that will impact your decision making that Vanilla UI doesn't show.
Shinies - A better Auction House.
In my opinion, these are the only addons you'll need.