Is Focusing On One Type Of Damage Best Or Worst Than Focusing On Multiple/all

I've started to build my character an I don't know whether to focus on one or more damage types and which ones are the best.

 

It really depends on your preference. There is no "best damage" per se, but if you find yourself investing a lot into one skill, such as Defense, you'll probably want to go for the respective elemental damage.

 

later on you’ll find that most anything flies for most of the classes, early on just build whatever you want around a single skill or set of skills