Hi, I need help guys, pls be fast

Hey guys,
I have been doing a project for my school,
I had to build a drone, so i strated doing it with ardupilot, i mounted my drone and everthing was ok but when i tryed to make my drone fly only spined 2 motors so as i didn’t do it before i calibrated the ESC, but i found with a problem. Now when i power on the drone the motors starts beeping very fast and doesnt response. I tryed to calibrate my radio but it stills beeping. And for making it more funny now i tryed to arm the drone and it says “arm rotor not spinning”.
Also if i connect the RC to a motor without APM 2.8 it works perfectly.
Pls help me guys it very important for my career.

What Hardware? What firmware? have you read the wiki on how to calibrate the motors? Did you maybe miss step? APM 2.8 is ancient. Are you sure you are using that? How fast is fast beeping? Once per second? 4 times per second?