To get started with Android, you'll need to get familiar with Git and Repo.
To initialize your local repository using the CAF AOSP trees, use a command like this:
repo init -u https://github.com/Nougat-Athene/android_manifest.git -b nougat-7.0
Then to sync up:
repo sync -f -c --force-sync -j64 --no-tags --no-clone-bundle