Buenos dias is not a question soliciting a response, technically. However, the usual response is probably "igualmente" (same to you).
Buenas Tardes
In buenos dias, there is only an accent over the 'i' in the word dia.
buenos dias, como amaneciste? buenos dias, has dormido bien?
'good morning sunshine' in Spanish is (word for word) 'sol de la mañana buena', but I think you mean 'Good morning, sunshine' (a greeting, plus 'sunshine') Good morning = Buenos dias 'Sunshine' as an affectionate nickname is not usual in Spanish, but literally = solana. So 'Buenos dias, solana'.
buenos dias = good morning in spanish
Buenas Tardes
Buenos dias Alberto mean "Good Morning Alberto"
"¿Buenos dias, Senorita (name), cómo esta?" (How are you?)
Buenos: Dias Noches Senor Senora
"Good morning to you" in Spanish is "buenos días a usted / ustedes / ti / vosotros, as"
Good morning = buenos dias
In buenos dias, there is only an accent over the 'i' in the word dia.
buenos dias, como amaneciste? buenos dias, has dormido bien?
mundo de buenos dias means good morning world
buenos dias = good morning in spanish
'good morning sunshine' in Spanish is (word for word) 'sol de la mañana buena', but I think you mean 'Good morning, sunshine' (a greeting, plus 'sunshine') Good morning = Buenos dias 'Sunshine' as an affectionate nickname is not usual in Spanish, but literally = solana. So 'Buenos dias, solana'.
Buenos dias. ¿Cómo estás? If it is a formal situation: Buenos dias. ¿Cómo está usted?