For the ennemy to look towards the player,use in System the "Compare Value"
Player.X>Ennemy.X -> Ennemy Set Not mirrored
Player.X<Ennemy.X -> Ennemy Set mirrored
To make him walk, give to it the "Platform" behavior and disable default controls. Use the same events as above, but change the actions.
Player.X>Ennemy.X -> Ennemy Simulate Control Right
Player.X<Ennemy.X -> Ennemy Simulate Control Left
Hope this helps!