I've been using QWERTY as a non-touch typist for around 17 years, and managed to get to around 25-35 WPM with it, but have experienced certain amounts of wrist pain/finger numbness from time to time. Started to use colemak a few days ago while also starting to learn how to touch type. I did a key cap switch on my keyboard to the layout, so in case someone else needed to use the computer they could. For learning the layout I used the AHK on-screen keyboard for the first couple days, and have been going without it since(while only glancing down from time to time to look at the number keys which can be hard to reach for accurately.). I'm not really looking to get to an über speed at it, but would like to get up to at least 40 WPM at it.
At first I only got like 8-10 WPM(89% accuracy.) with it, currently getting around 14-18 WPM(92-94% accuracy.) with it after 5 days of typing on it, and at a few hours a day(mostly casual typing.). I do find myself hitting the c key with my index finger and not the proper middle finger(Much easier to reach with the index.), and find myself running into the relatively common ct bigram doing that though(act, fact, active, etc.).
For the speed tests I've been using Amphetype and 10fastfingers(I prefer Amphetype over the other, I do a bit better when I don't fell pressured by a time limit.).
As for adapting to the layout, I do notice the load on the right pinky, as not being a touch typer before and a gamer, my left pinky is a bit stronger than my right, and easier to control. Like for O letter typos, I sometimes will drop an O out of a word or hit I with the ring finger instead by accident. I have like 4 times the number of errors on the O key than I do on the A key, 92% versus 98% accuracy.
Edit: Top speed so far for today is 19.9 WPM(93.8% accuracy.).