Magic The Gathering: If a card says "Deals X damage to target creature or player", can a creature block if you target the player?

Answer 1

No, because its not an attack.

Creatures can only block attacks. This is direct damage which can not be bocked.

Answer 2

No. 'Blocking' is what you do in the combat phase, against attacking creatures. There is no such thing as 'blocking' a spell, a damaging one or otherwise.