Configure Code APM 3.2.1 in arduino


I am new to this forum, first of all try to speak English as best you can hahaha :laughing: :laughing: .

My problem is this, I want to know how to set the code that is compiled into Arduino (apm ArduPilot 3.2.1) and whether there is a guide or documentation to talk about the code, Iā€™m following two guides this and this

thank you very much for your time, and I welcome your comments