I read your script and it’s an interesting premise: an astronaut dreams visions seen through a crow’s eyes.
A few suggestions, for your consideration.
To me descriptions of settings should be minimal in a script, in contrast to a typical description in a novel.
Initially, the tree is seen with the setting Sun on the
right, then the camera comes closer and stops near a branch
where two crows are sitting, admiring the sunset. The crows
are seen from behind. The camera angle changes, and the
crows are now seen from the front, their faces illuminated
by the last rays of the Sun.
On a branch of the tree sit two crows, admiring the sunset.
At the same time, I think you want to provide greater descriptions of the astronauts and what they are doing:
Two astronauts, one sporting a beard and eating borscht, the other wearing a baseball cap and reading a tech manual.
I liked the dialogue of the crows, interesting and good pacing. Would be willing to read your second draft to see what happens next.
Regarding script software, I like Final Draft. It’s what the Pros use so you know that it will be compatible if you get involved in a writing project. It’s expensive, but well worth it, IMHO.