most of the hypervisor programs are not insanely difficult to use.
if I'm honest I think I like virtual box the most of all the "home" ones available, it's the least hassle. (and it seems to require the least resources of the host machines - I can run VMs on my windows tablet.)
that said.
virtual box is not used in enterprise. so those who don't already work in the industry but want to may have a more relevant learning experience using hyper-V (comes as a free thing using windows with the highest license level (e.g not home/basic)
Vmware player is completely free, and the settings screens look a bit like (same icons etc) Vmware.
that said vmware esxi is also free. it's just the licenses to do the really cool things, (liv migrations, DRS, fault tolerance managing clusters etc that are paid features.
you can setup a host as you would in a proper private cloud solution, and use vsphere client to manage it. you just don't get to have clusters etc for free.
open stack is also free. but last I heard even guys who helped develop it stopped using it...
if you're on linux. then there are a fw native things depending on your linux flavour they may be called diffrent things.
most are based around QEMU, coolest thing about that is it does hardware emulation for different processor types.
It makes it more powerful than any of the existing enterprise hyper visor solutions. but it's a real pain to setup with a steep learning curve for new people. (unless you have some graphical manager attached to it)
