Complex sentence: Paddock arrived at the Mandalay Bay hotel on September 25,2017, and occupied a suite on its 32nd floor, which was diagonally adjacent to his shooting targets in the festival lot.
Split into simpler sentences: Paddock arrived at the Mandalay Bay hotel on September 25,2017. He occupied a suite on the 32nd floor of the hotel, which was diagonally adjacent to his shooting targets in the festival lot.