The Dueling fighting style doesn't seem to state anything about shields, stating that the character can only wield one weapon while fighting to gain the benefit. Does a shield count as a weapon or ...
One of the pregen fighters in the Starter Set has proficiency in simple & martial weapons, giving a +2 bonus, but also has the Archery fighting style, giving a +2 bonus. I don't see these added ...
Taken from the Player's Handbook - Fighter's Fighting Styles (p. 72) Dueling When you are wielding a melee weapon in one hand and no other weapons, you gain a +2 bonus to damage rolls with that ...