Were the Spaniards the first Europeans to introduce firearms to the New World?

Yes, Columbus had several firearms (arquebus and small cannon) with his company in 1492. The conquest of Mexico and Peru (1519 and 1527 respectively) saw limited use of these weapons against the Aztecs and the Incas. More effective, and terrifying the native populations even more were the large horses the Spaniards brought with them. Cavalry, lance, the broad sword and crossbow were far deadlier than the primitive and clumsy firearms of the time.