Easiest class to play as a beginner?

As said above - that would be ARC and ACN in that order. (Archer + Arcanist)

Someone said CNJ, while I never struggled and still switch to help my free company, I've seen some really bad healers so it can't be too easy. Archer is easy peasy though.

I'd say Arcanist is the easiest. Especially after you get the topaz carby pet. I was so incredibly bored with arcanist that I got it to level 23 and switched to archer. At least with Archer I can move around not just stand in one spot.