First off, I want to make it clear that the distro doesn't really matter. Different distros are just what it comes pre-packed with by default.
TLDR:
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For something easy to use: Linux Mint
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For something that has pre-installed audio software (but maybe not the ones you want): Ubuntu Studio
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If you want to build your system from scratch: Debian (or Arch if you want the latest and greatest software, and don't mind the occasional update breaking your system around once a year or so, and needing to spend an hour fixing it)
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Regardless of which distro you get, use JACK or PipeWire for your sound server. PulseAudio (on its own) has too much latency.
More details:
I first tried Ubuntu Studio. It comes with a lot of software related to audio production. But I found it to be insanely slow, and it didn't even come with Reaper anyway.
I tried OpenSUSE because I liked that it had the option to manually deselect the software you don't want (and I was too much of a beginner to know how to pick my packages from the ground-up). It worked well.
Eventually I moved to Debian. I didn't want any of the extra fluff and found it was pretty easy to choose everything myself. One thing that's important is that you don't want to use PulseAudio. Either use JACK (which I think needs to be used in conjunction with PulseAudio actually) or use PipeWire, which is what I use.
For any Windows software, use Bottles to emulate them on Linux. I actually ended up needing to go back to windows because of one audio software: Wwise. There was no way of running it in Linux. A VM probably would've worked, but that would've been a massive hassle for how I'd need to use it.
Free Linux VSTs: https://vital.audio/ https://lsp-plug.in/ https://github.com/TukanStudios/TUKAN_STUDIOS_PLUGINS
Paid Linux VSTs: https://www.acmt.co.uk/products/index.html https://librewave.com/ https://www.audiodamage.com/collections