For starters, you could use the Pysense board (which has a light sensor and a basic driver) and the AWS example to push the data to AWS IoT. This should work out of the box. What you do in AWS IoT is another topic.

@matthew look at attenuation https://docs.pycom.io/chapter/firmwareapi/pycom/machine/ADC.html#adcchannel--pin-attnadcattn0db try ADC.ATTN_11DB