From a user perspective, Distrobox is a tool that lets you "spin up any distro inside your terminal".
You can basically create a mini Linux environment of any distro that you can access through the terminal. You can set it to share your home folder, our create a new home folder just for that mini environment.
Behind the scenes Distrobox is creating and managing containers through Podman or Docker. You could technically achieve the same thing by manually setting up Podman containers, Distrobox just makes it very easy to create and maintain those containers with the correct permissions. It also has useful tools where you could install an app in a Distrobox container, but then add that app to your host OS app list.
This makes it especially useful for immutable OSs. Instead of adding packages to your base OS, which should be kept as minimal as possible, you can just install them in a Distrobox, so your host's root filesystem is unaffected.
I would go from the bottom up instead of top down.
Make a list of software and tools you use, and search for functional Linux native equivalents. Then find the distro that supports up to date versions of that software (through flatpak or the package manager).
You can honestly do 100% of this without even touching the command line if you choose something user friendly like Mint, Pop OS, Ubuntu, or Fedora. Don’t fall into the rabbit hole of finding the perfect distro. Go from what you need to what supports it.
keep the windows partition around for a while until you are 100% confident you can fully make the switch.