OK. So what is the purpose of the arduino in your project?
Yeah I know. But isn’t an ESP8266 alone enough to handle your project?
A good place to start would be to connect the ESP8266 to the internet, and learn how to upload some arbitrary text and data.
When that is working, add a sensor, collect some data and upload that. Repeat until all sensors have been accommodated. If you run out of pins on the ESP, then you might consider using a different processor with more pins, or add a second processor.