Some info might be outdated, but you can get the gist if it is. Current manifest is for building oriole, but you can add your device and vendors to benzorom.xml and sync.
To get started with Benzo, you'll need to get familiar with Git and Repo.
To initialize your local repository use a command like this:
repo init -u https://github.com/BenzoRom/manifest.git -b android13
Then to sync up:
repo sync -j$(nproc --all)