Hi

Just wanted to be sure about this:

I am playing the tutorial and its the enemy turn.

A Giant wolf is activated from the shadows

its second effect says: This enemy engages the hero with the most wounds.

Am I correct in assuming that since none of my heroes are wounded the Wolf does not engage any hero but stays in the shadows?

No, when there are two equal choices it's left up to the players to decide. the wolf will still engage a Hero.

Would the wolf disengage from one hero to engage another?

Would the wolf disengage from one hero to engage another?

Yes.