'aap kaise ho' = How are you? (in Hindi)

'aapan kase aahaat' or 'tumhi kase aahaat' or 'tu kasa aahes' in Marathi. (in decresing order of formality)

Maaza naav Celine aahe. Tumhi kase aahat? Sukhi raha (khush raha). Hardik shubhechchha.

'tumhi kase aahat' is more polite that 'tu kasa aahes'. But both are fine. Marathi is anyway somewhat informal.

Hardik shubhechchha = best wishes

My first entry in Marathi

Aap kaiso ho. =  TUMHEE  KASAY  AAHAAT

Maza nav Celine aahe. Tu kasa ahes? Sukhi raha. Hardik subhecha.

I wish you a ' VERY  HAPPY BIRTH DAY '  =  Waadh divsaachyaa  HAARDIK  SHUBHECHAA.

Hi..

My first entry in Marathi

"Aap kaiso ho". Maza nav Celine aahe. Tu kasa ahes? Sukhi raha. Hardik subhecha.

Only the part in pink is wrong. All the other sentences are correct. It should be "Aapan kase aahat?", which means "how are you (people)?" Best of luck for learning marathi.