https://learn.dvorak.nl/ <- used this to learn dvorak. I really liked how I didn't need to switch my layout at the computer level just to learn.

https://zty.pe/ <- used this to practice and get my speed up, regardless of dvorak/qwerty/azerty. The way it plays, the ramping up of word length and frequency, I find more effective for "locking in" the positions in my mind and fingers. Especially once there are several words on-screen; you need to actively choose which one you're going to type next instead of the program choosing for you. In my experience, that added active part of the process really helps expedite the formation of muscle memory.