logged in as configurationadmin go to catalog, there's already a blueprint "vsphere initial setup" so you can connect to your vCenter.
if the catalog tab does not exist, log out and back in again. it takes a couple of minutes for this to be populated after installer finishes
when you rtun that workflow make sure the "endpoint name" matches exactly what you configured during the installation at the point where you configure the vcenter settings. most people seem to use "vCenter"
Kalli