Bravo, mi amigo!
Or: Un bueno, mi amigo!
Amigo is one way of saying friend in Spanish. Amiga is for a girl.
Eres mi buen amigo
You would say "estoy bueno, mi amigo/a".
Buenas noches, amigo (amiga).
To say hello friend in Spanish you can say "hola amigo".
Para mi buena amiga Teresa
In Spanish it sometimes matters if you are talking to or about a male or female. If you are saying 'good night my friend' to a female it is 'buenas noches mi amiga' instead of 'amigo.'
my friend = mi amigo
Translation: Que tengas un buen dia amigo.
Eso esta bien parar saber amigo
If you're speaking to a close friend, you'd say, Es bueno que no estás trabajando.
Best of luck to you my friend is very easy to translate. Best of luck to you my friend = mejor de las suertes a mi amigo