Header

Hi Guys,

I searched the entire forum and guides but could not find an answer.
I want to use the header pins of my LattePanda Delta (so not the arduino side) but I can't find any documentation on how to address them.
Does anyone have any tips for me on how to use the header pins like USB/I2C for example? 
Are there any instructions for this in the meantime. In an ancient post it once said that the docs are adapted to this, but that was 2018....
I am using the Lattepanda with Windows 10 and the goal is to create a console application with Visual Studio.