Along my CW journey – which I am still trudging along on – I have benefited greatly from Kurt Zoglmann (AD0WE) and his site Morse Code Ninja (link).
Kurt has produced literally weeks and weeks of audio files of various categories in speeds of 15-50wpm (*gulp* – that speed just sounds like noise to me still), all of which is freely available for download. You can see the dozens of categories on his Practice page (link).
His YouTube channel additionally has videos of the audio files so you have multiple options for playback.
Given how many hours I’ve spent using his work over the last year plus of my learning CW, and how many others I’ve spoken with that have also benefited, I am suggesting that a small donation to continue to fund his efforts is a good thing that, if able, you should consider doing.
He has a link to do so on his contact page (link).
No I am not affiliated with him or his site, just a very grateful consumer of his efforts.
Having a software development background I know how time intensive projects like his can be, and for him to put it out there for everyone to use freely speaks to his love for the hobby and desire to grow it even more. Hosting a website and having bandwidth for file download isn’t cheap, and I like to encourage people like him to continue so that we can all benefit for years to come.