1. What was the Yalta conference?

2. What was the goal of the conference?

3. What actually happened at the conference?

4. What were the consequences of the conference?

For 1 it is  

The Yalta Conference, also known as the Crimea Conference and code-named the Argonaut Conference, held February 4–11, 1945, was the World War II meeting of the heads of government of the United States.

for 2 it is The primary purpose of the “Yalta Conference” was to discuss the re-establishment of the nations of war-torn Europe.  

for 3 it is meeting they did a lot of meetings.

for 4 it is  optimism for the future of the continent.

that is probably something for you to answer