Five steps from a problem to its solution.

Help me design and build a first working prototype for this problem in Visakhapatnam, Andhra Pradesh, India.

Problem: People in Visakhapatnam aren't warned ahead of the winter months when the city's air turns poor or very poor.
Who it hurts: Residents of Visakhapatnam, including children, older people and people with asthma or heart disease, and those living near the port and industrial areas.
The moment it hurts: A December week when every daily reading is poor or worse and there is no local warning or advice for that neighbourhood.
What people do today: Readings come from a handful of manual and continuous stations, and residents have to look up the national AQI themselves after the fact.
Why it is still unsolved: Monitoring is thin and uneven across the city, the sources of pollution have not been quantified, and the seasonal pattern isn't turned into advance warnings.
What solved looks like: A free neighbourhood air alert for Visakhapatnam, by SMS and web, that combines official station readings with forecasts of winter inversion conditions, warns a day ahead when air is likely to turn poor, and gives plain health advice.
Where: Visakhapatnam, Andhra Pradesh, India

First, list what you would need to learn from the people affected before building, as interview questions.
Then propose the simplest version that would help, the screens or messages it needs, and the data it would use.
Keep it cheap to run, accessible, and respectful of people's privacy. Flag anything you are unsure about instead of guessing.