How do you say Hello in French? Greetings and salutations.

Good day! Good morning! Good afternoon!. . .Bonjour!

Hi!. . .salut!

Pleased to meet you!. . . Content(males) or Contente(females) de te rencontrer! More literally 'happy to meet you'. The formal version is. . . Content(males) or Contente(females) de vous rencontrer!
A common, more formal form of this is enchanté 
Thank you! ... Merci

Thank you very much!. . . Merci beaucoup!

Good evening!. . .Bonsoir! Bonne soirée!

Good night!. . .Bonne nuit!

Come here! . . . Viens ici!

OK! . . . OK!

How good! Great!. . .C'est bien! Super!

How are you ? ... Comment vas-tu?

How are you ? ... Comment allez-vous?

How are you? ... Ça va?

I'm doing well ! ... Ça va! Ça va bien! 

Good luck!. . .Bonne chance!

Until next time! ... À la prochaine!

See you soon!. . . A bientot ! J'espére te revoir bientot!