To get started with Android, you'll need to get familiar with Git and Repo.

To initialize your local repository using the YU-AOSP trees, use a command like this:

repo init -u git://github.com/yu-aosp-n/platform_manifest.git -b n

or for syncing through GitHub's SSH Transfer,

 repo init -u git@github.com:yu-aosp-n/platform_manifest.git -b n

Then to sync up:

repo sync -j6 --force-sync -f --no-tags --no-clone-bundle