I recently did another small "knowledge pill" course at Udemy, Vagrant Quick Start: Virtualized Development Environments.
I knew it would be introductory and didn't expected much, and in that it delivered: You get to know what's Vagrant, how to install it, and the basic operations of managing VM instances, SSHing into it, provisioning and updating boxes, and where to find baked up VMs. Just beware that out of the 2 advertised hours, almost half of the time goes in basic and advanced versions of "how to install" on Mac, Windows and Linux.
Other than that, professionally build, really well explained (one of the few times the speaking cadence was so nice I chose not to speed it up!), big visible fonts and easy to follow examples. The author has a more advanced course which I'll definetly consider doing.