Home page of the FUA3 branch, here you will most likely see tutorials for Arma 3's 3DEN Editor and perhaps some scripts that you can use for your own missions.
to be continued
Here you can read upon some documentation which will help you start making missions. Study the documentation from top to bottom, as it follows the general flow of mission making.
You can use these tutorials to make your mission better, or more complex.
You can use some of these scripts to make your mission more interactive.
You can read through this module to learn the basics of Arma 3 and basic functionalities of our modlist.
You can read through this module to learn the basics of jets in Arma and how to fly them.