I'm downloading the installer as I type this. I've just recently discovered the miracle of private servers; I've been playing on Atlantiss's 4.3.4 server for the past few days leveling a prot warrior. I thought about trying out a Vanilla server, but I decided against it as I really wanted to come back to the WoW that I remember the best (Cataclysm). I started my trial version of WoW at the very tail end of WotLK maybe a month or so before patch 4.0.1. I remember walking out into the Valley of Trials with my Troll Hunter and being absolutely amazed.
I was hooked. However, after the dreaded Troll Heroics came in Cata I stopped playing for a while. I only stepped foot in a raid a handful of times during my longest run with WoW, and since then I've played off and on, coming back most recently to MoP when Warlords of Draenor was announced. However I realized why I had been burned out before when I started doing dailies and running around that damned island that I can't even remember the name of off the coast of Pandaria.
Now, I've been watching videos about private servers and doing research and I really want to try playing Vanilla. I'll admit I'm a bit intimidated considering that I was a Cata baby. However, I think this experience will be just as wonderous as when I created my first Troll so many years ago, even if I may be a bit dumbfounded by how different Vanilla was.
Anyway, now that I've shared my general history with WoW I'd love to hear whatever advice any veterans can give me. My main on retail was a Frost Death Knight and I've had a little bit of experience with every class. I had a Ele/Resto shaman and a Prot Paladin that were both around level 60 when I most recently quite playing. What class should I consider playing? How hard is it to find a group as a DPS? What is PvP like compared to Cata? There's more that I can think of but I'll leave it at that. If there's any other advice you'd like to give it will be much appreciated!