Seriously i play for long time ago but never know correctly this fact. When turn side A to side B during the set up.

When quest successfully and finish a quest card side B. When i flip to other card side A and B and follow the step ?

Thx for answer me.

Hard to read but here is what I suspect you want :

when finishing a quest, follow instruction on the side A of the next quest and then reveal it, i.e. turning it face B, and follow instruction. Then go on with the game.

thx