Being familiar with dnd 5e will give you a head start in the basics. Things like how ability scores and combat/social interactions can play out. But not necessary. They’ve changed quite a few minor things that deviate from the tabletop game that I’ve found myself having to actually unlearn dnd.

Monks are actually useable. Went with a 4 elements subclass. So I have a mix of spell-like abilities for range, and can still smack things with my staff and fist.

The main thing is, being aware of the micromanaging you’ll have to do in combat. Don’t be afraid to use consumables. And explore! I’m still only in act 1.( I’ve had pre release for over a year, so I’m taking it slow to see what changes are in the actual release).