What do we need to start

A Home Lab is a extended Home Server.

We need something to run VM's or LXC's on.

You could start with running VM's on your daily driver with Qemu/KVM or even VirtalBox. Then migrate to a dedicated HomeLab: a old PC, a Raspberry PI, a decommissioned server or DIY something - the choice is yours because they all work. A nice way to get started is to get some NUC's or Raspberry PI's.

Then we need to choose the OS and Hypervisor.

OS Linux is the first choice: very stable, free, open source, easy to learn and many sources for help.

Hypervisor stage 1 is on your PC Qemu/KVM is the best to use, KVM is nativ in Linux kernels (turning them into Type 1 hypervisors). You could also use VirtualBox but it's slow, buggie and confusing.
Hypervisor stage 2 is to have a dedicated Vituala environment like Proxmox, Xen or VMware. We have choices! (see this link for info on hypervisors)

Networking is important and you should pay attention to designing it with care. You will run a lot of networks and VLAN's. Level 2 managed switches are recommended.

My Journey

I started with old PC's as HomeServers on RedHat, migraded to Fedora, ClearOS and Ubuntu. I also shortly run some other propriety OS's including MS. Then I bought a decommissioned server from one of my clients for 100 €. Made it into a ClearOS server, it served us well for some years.
Then it was time to get a Hypervisor based system, tried VMware run XEN for some years and last year switched to Proxmox.

Later i have made many old servers and currently I have 4 old HP servers. One NUC one DIY backup server. My development PC is Arch Linux based and has Qemu/KVM and VirtualBox for regular tests of software and evaluation of Desktops. A also have a set of laptops with different versions of Linux and a Win10 laptop.

Current Lab

The current Lab runs Proxmox: The NUC is for testing small high speed apps on vm's. The main Lab is 2 servers running all production and test apps. One is dedicated to production and uses the other as back-up migration.
My back-up's are on the Proxmox Backup Server (DIY server).
TrueNAS is for more back-up and holds the templates. It also run some production apps.

What is Proxmox virtual environment

Proxmox is an application set running on top of the famous Debian Distro. By using may standard tools like CoroSync, LXC, QEMU. KVM and ZFS Pools.

ZFS Pools are recommended by Proxmox to use for Storing your VMS.
It gives you more performance and Redundancy.

Proxmox VE is an open-source SMP (server management platform) for enterprise virtualization. It tightly integrates the kernels KVM hypervisor, QEMU and LXC, software-defined storage, and networking functionality - all as a single easy to use platform with a nice GUI.

Networking is important and I run a lot of networks and VLAN's. You will too.
I have one dedicated network running between only the servers. Designed for high speed communication and data transfer for the servers and their apps. Example HA: we can have the vm's disk on the NAS or run a simulation with desktops having disks on the NAS.

I use managed Level 2 and 3 switches with web configuration interface.

Remember the Command Line Interface is your best friend - I ♥️ CLI