santhosham dewali valthukal
"Eniya deepavali nalvaalthukkal" is happy Diwali in Tamil.
Andhariki Deepavali Subha-kankshalu.
To say "happy journey" in Malayalam, you can say "സുഖമായ പ്രയാണം" (sukhamaya prayanam).
You can say "Pongal Vazhthukkal" in Tamil to wish someone a happy Pongal.
In Hindi you say: Diwaali ki mubaarak ho or Shubh Deepavali.
Fuku tamina is happy wedding in Tamil, hope this helps you :).
Santhosamaaga Iru
We call it in Tamil, Deepavali. (dee-pa-va-lee)
Navaraathiri Nalvaazhthukkal
You can say "நான் மகிழ்ச்சியில் உள்ளேன்" in Tamil, which translates to "I am happy."
Putthaandu Vaazhthukkal - is Happy New Year in Tamilஇனிய தமிழ் புத்தாண்டு நல்வாழ்த்துக்கள்
You can say it in these ways: Happy Dewali Happy Deepawali Dewali Ki Subh Kamniya.