On top of what others said, be aware that spins are just that… a “twist” on the main offering – most of the time if not every single time you can “convert” one version of a given distribution into another with varying amounts of effort.
For instance, the security spins of any distro (or GNU+Linux flavors, as I fondly like to refer to them) are just the baseline version of your GNU+Linux distribution plus the security-focused tools.
Security spins are created because if you need something like that, it is most likely you won’t be doing any audio/video processing… or playing games… or doing traditional office work… or some expensive computational operations – you’re interested in something in particular hence you strip everything that’s not necessary for that purpose out of it. That’s why it is highly unlikely (not impossible tho) that you’ll find a good chunk of security-focused tools in a spin dedicated to multimedia edition.
Other than that, all those spins are generally the very same thing. The only noticeable difference I can tell about Fedora spins is the Core OS and Silverblue spins, which ships dramatic differences regarding how the base system is put together, as they are not only very focused on doing just one thing and doing it well (i.e. Core OS spin), but also a testbed to evolve the whole distribution to a new level (like Silverblue is).
I’d suggest you pay a visit to places like Distrowatch.com, LWN.net, fsf.org, or Phoronix, and start learning about the different kinds of distros that exists, like binary vs source-based, fixed-release vs rolling-release, to learn how a GNU+Linux distribution is put together, what is a “package manager” and what are the commonly known ones, what are Flatpak and Snap (this way you’ll realize how insanely cool is Silverblue approach), what are the most common file systems and which one would best suit your needs… and of course, you can just cross the street and learn about the BSD, Minix and other Unix-like, Unix-inspired and also not-Unix-like or Unix-inspired operating systems out there. There’s also this other cool OS called Emacs, that a lot of people use mostly as a text editor of all sorts.
I just started learning guitar. It is the same thing, almost: which one should I take? Which strings should I use? What kind of amplifier will suit me best? What pick should I try? What music method should I devote my time studying?
You just build your rig and begin your journey.
It’s impossible to see the end of the rabbit hole from where we stand, don’t overthink it. Keep your mind open to learning new stuff and you’ll do great