There will be different answers depending on who speaks the language, where, what the community attitudes are to it, and what kinds of resources you have access to.
One starting point is Kat Li’s answer to How can modern society preserve dying languages?
From Wikipedia, it seems Kumaoni is in the same category as a lot of languages in Indonesia: being spoken by millions of people, but they’re unlikely to pass it on, because everyone is switching to the national language.
The most obvious think you can do, as an 18-year old student:
- Use it.
- Use it with other people.
- Make Kumaoni language clubs, to make its use visible in university.
- Use it online. And that includes texting in it.
- Use it in ways that can enhance its prestige. You know how better than I can.
- And don’t get too precious about the purity of Kumaoni. A Kumaoni with a whole bunch of Hindi (or English) words in it is still better than no Kumaoni at all.