Come from WoW. Which class is the best for me?

[Hestzhyen]

If you're going to DPS in XIV, you're going to have to get used to 15-20 buttons being pushed in the correct sequence to do damage. That's just how the game is. Even healers and tanks have lots of buttons- you can't escape it, though you can control your learning experience.

I don't know WoW classes that well but if you're looking for something gentle and not too complicated, RDM really is your best bet. It's straightforward, intuitive to pick up, and you don't have to worry about many combo chain sequences like other DPS do. Even mediocre players can get good damage from the job- you only start to notice the fall-off if you are good enough to be in the top 20% of players or so. The only drawback to the job is that it starts at 50 and you need another job at 60(?) to unlock it. In my personal opinion I found Black Mage to be relatively easy to pick up too- it's dead simple up to 50 and the additions after that change how you play but don't add too much overhead. So you could give Thaumaturge/BLM a try to see if being a nuke turret is a good fit.

DRG is also straightforward as far as melee DPS go but it has a LOT of buttons to push in a specific order. If you don't like where it's heading already, you might want to switch. BRD is even worse in that way- you're constantly pushing buttons and managing DoTs, procs, buffs, and songs as you do fight mechanics. It's fun as heck but I don't think I'd recommend it to a beginner who's scared of APM with a large selection of skills to be used.

Last note: if you aren't going to be a hard-core/speedrun raider then RDM is fine. People love it for prog especially, and since it shares most of it's gear with SMN and BLM, you can switch to those higher damage dealing classes after you have the fights on farm if you want to. Regardless of what the meta dictates, all jobs really can clear all content if the player behind the screen is good enough. So don't feel pressured to take a high value job just because it's currently in demand for O8S speedkills.