"Pórtate bien" means behave yourself.
"Estar bien." means to be good. (You should conjugate that before using it in a sentence)
I would say, compórtate. You could probably say comportate bien.
"Bueno" means good in Spanish.
To say "You are good" in spanish you say: eres bueno
bueno is good in Spanish.
"Real good" is "bueno verdadero" in Spanish
"Good morning" in Spanish is "buenos días".
No muy buena is the best way to say "not very good" in Spanish.
buneo
Bien.
.
¿estoy muy bien y tu?
Adios
Bueno!