Check this link which might help with esc calibration:
https://community.dojofordrones.com/t/stuck-in-esc-calibration/574
Arming/disarming is easiest using the throttle stick.
Arm - right lower corner, Disarm - left lower corner.
Alternatively, you can program a controller switch.
The safety switch, if used, must first be turned off to arm. Note some GPS modules have integrated safety switches.
Let me know if that does not help.