When did brazil organize its first world cup?
No context provided
When did Brazil bid for its first World Cup?
1946 FIFA Congress
No context provided
When did Brazil organize its first FIFA World Cup?
24 June to 16 July 1950
History of the FIFA World Cup
https://en.wikipedia.org/wiki/History%20of%20the%20FIFA%20World%20Cup
The 2014 World Cup was held in Brazil, marking the second time that Brazil hosted the competition
History of the FIFA World Cup
 Brazil and Germany had been the leading bidders to host the cancelled 1942 World Cup; since both the 1934 and 1938 tournaments had been held in Europe, football historians generally agree that the 1942 event would most likely have been awarded to a South American host country. Brazil's new bid was very similar to the mooted 1942 bid and was quickly accepted.
1950 FIFA World Cup
This tournament ended the hiatus. Uruguay, who had won the inaugural competition in 1930, defeated in the four-team group match final the host nation Brazil 2–1.
1950 FIFA World Cup
The FIFA World Cup has been held in Brazil in two different occasions. The country was one leading bidders to host the cancelled 1942 World Cup and presented a very similar bid for its first World Cup in the 1946 FIFA Congress, which was quickly accepted. The competition would be then organized from 24 June to 16 July 1950, when Uruguay defeated the host nation 2–1 in a four-team group match final.