arduino nano rfid code programming

hey evreyone i need help with writing a code for my project
the concept of the project is a smart mail box that open with rfid
i use arduino nano with rfid-RC522 my problem is with the code i dont really know how to get them together
someone know a simple code for this to help me start or a guide
only need to get the buzzer work when i use the chip or the card even to get something write on the screen will help me in the start

this is my electric scheme :