It really depends on what exactly you're trying to achieve. If you just want to start some virtual machines to test things, probably the simplest option is to use something like VirtualBox (free) or VMWare (paid), those are the two major options for desktop use. There are others, however, it might require more setup or a better understanding of operating systems and networking.
There are other considerations to take in mind, however, don't have much information to go on.
------------------------------
Nicole Daniella Murillo Mejias
------------------------------