This will depend on your proxemity with the perso you say hello to :
(a friend) --> "Salut" (hi) and you may follow with the basic greeting "Comment vas-tu?" (How are you)
(Someone you know apart from your job) --> "Bonjour" (Hello) then "Comment vas-tu?"
(Someone you need to be formal with) --> "Bonjour" then "Comment allez vous?"
this is the basic and correct ways to say hello but people in the street, young people and your friends may use a more degrated french