How how long will it take for me to be a reasonable speaker in Hindi?
I practice about 20 min per day, and I get outside help from my Indian parents. I started off knowing one or two sentence structures and a few basic verbs and adjectives. I’ve been practicing for a few days now.
Languages can take years to master. And not everyone has the same resources for learning, (like time, opportunity to socialize, talent for and skill with language acquisition, etc.) So, I don't know if anyone can provide a reliable answer to your question. But, that's really awesome that you are able to practice with your parents. I would imagine that will serve as an advantage. :)