Here are 12 blog posts that explain everything that you need to know about lxd/lxc:
(There is also good documentation available on the canonical site)
Once you have played around with it a little, you can just launch an instance from the Ubuntu: image site, to get started
Customize it to your taste - I install a standard user, webmin, and a few standard utilities like openssh for example.
This becomes my template on which I install Erpnext (and possibly other stacks which I might want to test or evaluate)
I publish some standard containers as images on my desktop and can access them from other machines, like a portable for example, or from outside
The concept is simiar to a VM, but much faster and more convenient. I have cheat sheets in evernote that I copy and paste from, since I wasn’t really a command line guy, but they work just fine