Let's Build
Do you have old hardware that isn't being utilized? If not, check around locally on places like Facebook Marketplace or recycle centers that resell. You may be able to find cheap or even free server hardware that you can use to host a hypervisor. I'll be using ProxMox, but there are other options out there, such as VMware or even cloud hosting, which will impose a cost.
I have a couple of older Mac Pro towers that are about 15 years old. I started on a four-core MacPro tower and realized that was a bad idea. This is something that you'll need to plan ahead on, but for now, my current Mac Pro tower has two CPUs with a total of eight cores and 32GB of RAM, and it's working great. You'll need to make sure you have adequate disk space as well as RAM.
