A book about a guy during the medieval times training to be a knight.

I read this book in the 8th grade in like 2012, but I believe the book was released atleast a decade before. The book takes place during the medieval times (i believe their may be a crusade going on, but im not positive). The protaganist is the second or third son of some lord and he is training to be a knight, but he sucks at first because he is left handed, and his dad makes him fight right handed, because his dad believes being left handed is a sign of the devil. The age range of the book was probably highschool to college level for content, but read relatively younger.