Paladin/Sorcerer, what is my spell attack bonus, ability, dc?

@kjdavis1288been playing with a character idea Paladin/Sorcerer for 5e (playing 4e now mostly), what is my spell attack bonus, ability, dc? proficiency is based on total character level. Ability is determined by which class you gain the spell from

— Mike Mearls (@mikemearls) March 17, 2016