Good Morning- Good morning.
Good night - Good night.
Sleep well - Achche se sojao.
Sweet dreams - Sweet dreams.
Had your breakfast/lunch/dinner? - Subah ka khana/Dopahar ka khana/Rat ka khana Lunch kha lia?
How was the day? - Din kaisa raha?
This just about sums up the state of Indian languages today.
@raj, honestly, these phrases that you mentioned, are hard to listen to in Hindi, even in towns. I don't remember hearing anyone say suprabhat (good morning) or shubh raatri (except Amitabh Bachchan on KBC)
Again, the breakfast / lunch / dinner thing is usually time sensitive - that is you usually ask that around that time. In that case a simple kha liya? (have you eaten) does the job. If however you are doing an end of day summary/ enquiry 😀 you can just use the English words rather than their Hindi siblings. The latter would actually cost confusion. For instance, if you want to tell someone 'go sleep in the bedroom', one doesn't use 'shayan kaksh mein jaake so jao'. Pointless really