You must create a virtual machine template before you can create an automated pool that contains full virtual machines.
A virtual machine template is a master copy of a virtual machine that can be used to create and provision new virtual machines. Typically, a template includes an installed guest operating system and a set of applications.
You create virtual machine templates in vSphere Client. You can create a virtual machine template from a previously configured virtual machine, or you can convert a previously configured virtual machine to a virtual machine template.
See the vSphere Basic System Administration guide for information on using vSphere Client to create virtual machine templates. See Automated Pools That Contain Full Virtual Machines for information on creating automated pools.
A virtual machine template is not for creating an instant-clone or a View Composer linked-clone desktop pool.