Short answers, pulled from the story.
The Anfa Hotel in Casablanca, French Morocco hosted the gathering from January 14 to 24 1943. US President Franklin Roosevelt and British Prime Minister Winston Churchill led their respective military staffs into the conference rooms.
Joseph Stalin declined to attend because the Battle of Stalingrad required his presence in Moscow. He remained in Moscow to manage the ongoing battle rather than travel to North Africa for the meeting.
US President Franklin Roosevelt announced a policy of unconditional surrender during a press conference on the 24th of January 1943. The declaration demanded total defeat for Germany Italy and Japan without negotiation.
Roosevelt eventually acceded to Churchill's approach for Europe as a compromise after General George Marshall lobbied for a cross-Channel invasion. This decision favored an Allied assault on Sicily followed by mainland Italy instead of immediate action across the English Channel.
He approved a US Navy plan to advance on Japan through the central Pacific and the Philippines which authorized the island-hopping campaign in the Pacific. This approval shortened the war while Churchill pledged more troops and resources to the Pacific and Burma.