Mint would probably work for you. Some stuff is outdated, but it has flatpak which is a package manager with more up to date apps. If you're willing to put in the time though, I'd recommend trying some of the more common distros out (Mint, Debian, Ubuntu, Fedora). You can use a liveusb to test them without installing.

Steam is available anywhere so that's not a problem.

Discord officially only has a .deb package, so that's only for Debian based distros (Debian, Ubuntu, Mint). There are other options for almost all distros though - I personally use Webcord

Fl studio might be tricky - supposedly it runs through wine but you might have to do a bit of work. I've personally used Reaper and I works great.

Adding to what others have said I also think Mint is a great option. But I strongly encourage you to install things via the package manager when available, I find that a lot of times when someone complains that something (that should work) doesn't work on Linux is because they're trying to install things manually, i.e. the Windows way (open browser, search for program name, open website, download installer, open installer, follow instructions), that's almost never the correct way on Linux.

Mint is probably the best install and go experience out there.