If you are going to get a purebred animal, educate yourself about the breed and find a reputable breeder. Whether you choose a purebred or mixed breed animal, you must learn about the breed itself. How a particular animal will act, look, and what it's going to take to care for it are essential things to know in deciding whether this is the right pet for you. If it is a mixed breed, investigate each breed in the combination if known. After an animal is spayed or neutered, there are few behavioral differences between males or females.
Opinions vary as to which sex has the gentler nature.