Use mouse to rotate 3D object and know which side is facing camera

So I’m wanting to do something similar to a lot of horror/puzzle games. Where items in an inventory are represented by a 3D object and can be inspected by the player.

So 2 parter I guess:
Is there a smooth way to have the item rotate slowly in the direction a player has click and dragged?

Can I I know when a side of the object is facing the camera (so player can inspect it and trigger a thing)?