Did Adam have to exercise faith in the garden, prior to sin?

Of course. He was a creature.

Creatures are utterly dependent on the Creator for everything, absolutely everything. That’s what it means to be a creature. An utterly dependent being is a being whose stance must be one of expectant trust.

God said, Eat from the trees. But how could Adam produce the fruit? He couldn’t. He had to trust God for food.

God said, It’s not good for man to be alone. Could Adam find a helper suitable to him? He had to trust God.

God put Adam into deep sleep and tore him in two. Adam has to entrust himself to Yahweh just as surely as Abraham did when Yahweh told him to sacrifice Isaac.

Adam went into deep sleep exercising the faith of Hebrews 11 - hoping for something delightful that he had not yet seen.