The functions you mentioned are not available if you use the free ESXi. You need to buy a licence that includes vCenter.
However you can of course clone VMs manually with the free ESXi ... its just not available via the UI
Correct, cloning and templates are vCenter Server functions.
Without those functions you will be manually copying, editing, and registering files.
Thanks you for your inputs.
What is my best option to get a copy of vCenter for lab purpose only?
You can evaluate it for 60 days, or for 12 months use buy a VMUG Advantage subscription.
Download VMware vSphere 7.0 Evaluation - Free Managed Virtualization for 60 Days