Do your vSphere installation first. Make sure that all SSL certificates are correct, and DNS and all that good stuff is done first. Have a separate cluster for your Management systems (vCenter/vShield/vCNS/etc) and your compute hardware for vCloud Customers (where they deploy VMs).
Then install vCloud Director. I'd suggest starting at 5.1.2 (current version).
Once you get vCloud installed and configured, you create a connection from vCloud to vCenter ... then attach the compute hardware cluster to vCloud.
vCloud on its own does not offer a billing solution. That's VMware Chargeback (entirely separate application)