Sorry for the late reply, but first things first, welcome to the game and the forums 
To answer your question, Conjurer should be the easiest to start with due to having ton of defensive options and pet support between Occultist and Shaman while the pets themselves are pretty strong and offer a tanky, laid back playstyle.
I would recommend this build for starting out as it is easy to assemble and pretty strong - Dark Rose - Lazy Dark One’s Set Budget Pet Conjurer