Add a Pms5003 and a bme280 and you can measure temperature, humidity, air pressure, CO2, and PM10 (particulate matter) all for about $45
Is there a tutorial on how to do this? Or what would I search for to find such a tutorial?
Start reading data sheets of mentioned parts. Stick them to some Arduino and write code. These measurements aren’t special in any way.
Though it really depends on what you want to do with the data, I can really recommend to use esphome in combination with homeassistant/influxdb/grafana. You can configure the sensors with a simple yaml file, compile and upload to the chip and then add it to a homeassistant dashboard. Long term trends can be queried from influxdb and presented in a grafana dahboard