Stalker is a beautiful movie but perhaps not the easiest one to watch, especially if you are not used to 10 min long shots of nature (e.g., water in a stream). Possibly Solaris, which you recommend too, would be an easier movie to watch first.
But yeah probably not easy if you’re not already fairly deep into art-house films.
I find it so relaxing that I’ve just learnt to enjoy the whole experience and enjoy the dozing as part of the experience of watching the film.
You have to allow yourself to be immersed in it. It's a slower pace than commercial film makers adopt, but the atmosphere builds.
Or mimoids.