Outdoor wall lights fall into two categories; lights for providing safety/security of movement and those used principally for decoration. You’ll want a light at your front door to be decorative and offer a warm welcome for your guests, be bright enough to see where the key lock is and also illuminate any steps leading up to the door. You may need a light at the back door, on the garage; these might be more functional, putting light where you need it.
Insider Tip! If you want your lights to come on automatically when they sense movement (a PIR sensor) install one separately from the light; you’ll have much more control over its function and have much more choice in the actual light.