Esp8266 no serial prints / connecting to WiFi and MQTT Broker problem

[bubuq]

So which one?

GPIO1 andGPIO3 are TX and RX. Can I use different pins e.g. D8 (GPIO15) and D7 (GPIO13) instead of GPIO1 and GPIO3? I followed a YT tutorial how to connect MAX485 and I got to connect to tx and rx ;/