What's the fastest way for a teenager to learn how to speak Indian?

I am 1/2 Indian on my dad's side. And I am a young teenager. I was wondering what is the fastest way for me to learn Indian. There are many languages spoken in India. My dad speaks Bangoli since he's from the part of India thats is close to Bangladesh. I think he speaks a little Hindu too. Is there a learning program that can help me learn how to speak both Bangoli and Hindu. I've heard of the Rosetta Stone program on tv but im not sure. (my Indian name is Nisha {just wanted to share that with you lol})