You have 4 ways to create VM depending of what you need:
You have no vApp or you want to create a new-one:
Click on Datacenters > Compute > vApps > New VAPP...
You want to include a new VM into an existing vApp:
Click on the vApps ACTIONS > Add VM...
You only need a sandbox vm without network for Software testing:
Click on Datacenters > Compute > Virtual Machines > NEW VM
A smart way to create a VM is to start from the Library Template:
Click on Libraries > Content Libraries > vApp templates > Select the Blueprint > CREATE VAPP