Kalis

I don't have strict constrains regarding screen time, but I try to use ereader as much as possible. For some reason e ink is much easier on my eyes, I can comfortable read even after a full day of work. No sore eyes or headaches whatsoever.

I'd say learn hooks from the beginning. Official react docs are still using class components but in a real world hooks are much more common. You can (and should) come back to class lifecycle later when you're comfortable with writing basic react code.

I believe there is beta version of react docs which is rewritten with hooks. I also heard good things about fullstackopen course.

Be sure to keep an eye on humidity in your room. I had the same problem until I've got a basic air humidifier and I feel much better now. I can work the whole day without problems.

You can try eink displays but there are still very expensive and refresh rate is subpar even for coding. They're excellent for reading though, much less taxing on eyes than usual tablets or phones.