Serial Monitor shows a continuous "word salad" without a loop
The ESP8266WiFi.h is for running on an ESP8266 host, but your are trying to use it on an Arduino Uno. This caused the crash of your sketch on Arduino Uno.
Based on the connection diagram you provided, you are using the ESP-01 as an wifi-shield and the ESP-01 by default is having an AT commands firmware. In order to use the ESP-01 as a wifi shield, you need an library like WiFiEspAT.