New to ranged targeting

Hi! Have only played melee specs my entire life. Trying out hunter for my first ranged spec and I’m confused by the combat targeting.

In melee, when a monster in the mob dies I am auto targeting to another target in the mob that I’m in combat with. With the hunter it does not automatically target another monster. He just says he doesn’t have a target and I have to tab target another one.

Am I doing something wrong? How do you guys go about this ?

There’s a setting in options to always target something in front of you that is within range.