Interested in Total War: Warhammer 3, where to start?

Hey all, I'm interested in picking up Total War Warhammer 3 and have some questions.

1. Do I need to have played the previous games or have them for any content purposes? 2. Do I need the various DLC for TWW3? 3. How many factions are included in Total War Warhammer 3?

Thanks in advance, any advice is much appreciated. :)