First of all, I will second the book recommendation from @Loud-living-dogma
Toxic Charity is a great book and important to read because our charity has the power to build lives as well as destroy them. Fortunately, the Missionaries of Charity have a pretty good track record, but the book is nonetheless a good, quick, and important read.
Second, I have never been to India. But remember that to many people, your face represents a wealthy, imperialist nation that a lot of people in the world resent. Don’t take angry prejudices personally, if you encounter them, and respond with humility and grace.
Finally, one of the hardest things about the work can be the disorganization and ambiguity. I’m an Anglo girl, at heart, having traced the vast majority of my family tree back to the British Isles! It was hard to spend entire days without specific objectives or feeling like I was “wasting time” and “not getting anything done.” Staying there as long as you can will help mitigate that feeling, (I was only around for a summer), as will carrying around a good book, truckloads of patience, and your sense of humor to roll with these punches.
Again, however, these were my experiences, and I don’t know what to expect for you. You sound like you have more maturity than I did, and I wish you godspeed on your journey.