google "leonardo pinout" and print a copy
google "UNO pinout" and print a copy
where the code has values like MISO & MOSI and Serial, you will see that both boards have pins with the same labels, but different pin numbers on different boards. the first thing to do is identify all of those and use the pin numbers you need for your Leonardo, not the pin numbers you would need for the UNO or MEGA
getting the code up and running by May 4th - good luck with that.