MODbus RTU MAX485, Arduino nano

Hello, I am in the very beginning stages of learning code and honestly, I'm stuck. I'm trying to learn how to write the code to read and write information to a controller using the Arduino nano and MAX485 rs485 driver. If I could get some help in the right direction. I have all the information for the Modbus on the controllers I just don't know how to get em onto my serial monitor or the internet.