Answer :

Nine of his ships sunk in 1494. Hunger and complaining of the voyage. 
being the youngest so it was hard for him to be able to say things because he was so young when he started. He faced fear, sickness, bad diets, stale food, mutiny, lack of food, and sea monsters (back then they didn't know that sea monsters were fake so they feared of them)  Christopher Columbus challenges were sickness, sailing, and death.