Here's a primer post I had from last year, I should freshen it up but I'll post it as-is for now.
We are going to need more people mixing songs so we can work through all the submitted vocals in time this year.
Here's a resource of torrents for plugins you can use to help you get started with mixing your vocals and stuff later on, I pulled all of them from RuTracker: https://files.catbox.moe/kcjndk.zip
Use Qbittorrent to get the torrents working.
We recently got Vocalign 6, a tool that lets you "sync" different stems of vocals automatically.
For audio software, I recommend REAPER. It's not as easy as Audacity, but once you learn it you'll be able to do whatever you need: https://www.reaper.fm/download.php
We have a mixing template for it, included in the torrent ZIP.
In case you have a powerful enough PC, this is what you can use to remove vocals from songs you've downloaded: https://github.com/Anjok07/ultimatevocalremovergui
In case you need high quality files for songs you like, the best bet is to find them using Soulseek: https://www.slsknet.org/news/node/1
And finally, in case your music only exists in the form of a Youtube video, here is YT-DLP. It's CLI, but it works well enough if you remember to use "yt-dlp -x --audio-format flac": https://github.com/yt-dlp/yt-dlp
YT-DLP has a few GUI implementations, such as TarTube: https://tartube.sourceforge.io/
