Arduino Uno connect ESP8266 Module issue

Hi all, recently i am learning about ESP8266 wifi module and i am still a beginner in Arduino.

I am referring the setup in this website:

However when I connect the ESP8266 to my Arduino to check the connection, I didn't get any reply from my Serial Monitor as mentioned. I had set the baud rate to 115200.

then i found another link which using different connection but still the same

the ESP8266 module i have is exactly same as the one in these 2 sample.

can anyone guide me through this? i seriously need your help. Thanks