Short answers, pulled from the story.
A Pacific Fleet was created in 1907 when the Asiatic Squadron and the Pacific Squadron were combined. This new force operated under a unified command structure for just three years before internal reorganization took place.
Admiral Husband E. Kimmel served as Commander of the United States Pacific Fleet at the time of the attack on Pearl Harbor. He assumed command after Admiral James O. Richardson was relieved due to opposition to long-term basing at Pearl Harbor.
On the 7th of December 1941, the fleet consisted of nine battleships, three aircraft carriers, 12 heavy cruisers, eight light cruisers, 50 destroyers, 33 submarines, and 100 patrol bombers. The fleet also included the Fourteenth Naval District commanded by Rear Admiral Claude C. Bloch.
Until May 1940, the Battle Force was stationed on the West Coast of the United States with headquarters, battleships, aircraft carriers, and heavy cruisers located at San Pedro close to the Long Beach Naval Shipyard. Light cruisers, destroyers, and submarines were stationed at San Diego.
The Submarine Force ultimately claimed 1,314 ships totaling about 5.3 million tons by the imperfect postwar reckoning of the Joint Army-Navy Assessment Committee. This sustained campaign of commerce raiding against Japan's merchant marine began the first day of the war.