Building air quality detector

I am new to IoT. I have seen IoT based air quality detector projects online. I want to build myself one. I don’t know anything about which hardware and sensors to use.
I am trying to achieve the following:
AQHI(air quality health index) is measured based on three air pollutants: ground-level ozone, nitrogen dioxide, and fine particulate matter. To measure the three pollutants use appropriate sensors and the data collected from sensors will be processed to calculate the air quality health index and then send to the internet. Air quality health index will then be displayed on either a web page or mobile app.

There is a sample library for the SPS30 that calculates the Air Quality Index for Particulate Matter, so you are 1/3 of the way there.

A forum search has lots of results for NO2 and Ozone.

I havent even bought the hardware yet. I am trying to decide which hardware to buy. For example, which sensors to buy, which microcontroller and how to have all the hardware ready. Can you give me information on sensors and microcontrollers available in the market which would be suitable for building an air quality detector?

I’d think that the first decision is connectivity. Do you want WiFi or Cellular ?
Then the Power… will you have a stable power source available ?

Wifi . I want to read the values from sensors, calculate the AQHI and then send it to a server through internet. Afterwards, display AQHI on web page or android app if possible. For power, I just want it to connect to my laptop