General objectives of the stage: Parking is the first out of three stages of the fourteenth mission of the campaign, entitled Attack of the Saints. The main objective of this mission is to eliminate seven Saints - high skilled female assassins dressed as nuns. Your first target on the list is Jennifer Paxton, because she's the one who will show up in the motel's destroyed room to verify if Agent 47 has been successfully neutralized.
The beginning of the mission is very linear. Continue through the tunnel until you've found an exit. Leave the tunnel and move to your right. Press the interaction key/button to squeeze through a tight spot. Eventually you should make your way to a destroyed hotel room (screen above). Take your time here to find Agent 47's suit and an iron that will soon come in handy in distracting enemy units.
You can now act in two different ways. If you don't have anything against playing aggressively, then consider taking cover near a damaged wall and waiting for Jennifer Paxton and her two bodyguards to arrive. Once they do use Hitman's Silverballers to eliminate all hostiles.
A much better idea is to make some preparations so that the main character will be able to surprise enemy units. In order to achieve this you must exit the hotel room as soon as possible. Turn left and make a stop once you've reached a corner (screen above). Hide inside the crate and stay there until Jennifer and Agency soldiers get to the motel room where you've found Hitman's suit.
Exit the crate once you've made sure it's safe and take cover behind a nearby pillar (screen above). Wait for one of the Agency soldiers to show up here, carefully approach him without being seen and eliminate him. I recommend dragging his body to the crate you've used to hide not so long ago.
Carefully return to the hotel room with Jennifer and the remaining Agency guard. You can use instinct mode here to shoot both targets at the same time or throw an iron to distract enemies and then kill each person with a silent melee attack.