This M5Paper weather station is refered from M5Paper Dashboard by estshorter at his Github: https://github.com/estshorter/m5paper-dashboard
Change your Wi-Fi parameters in src/WiFiInfo.h
Weather, temmperature, humidity, visibility, pressure, wind ... icons are converted to "C" codes and located at:
scr/WeatherIcons.c
scr/THPIcons.c
scr/WindIcons.c