Help a Newbie

MuseScore does not do real-time MIDI input. You could try recording into a sequencer program, saving as MIDI, then importing the resulting file into MuseScore, but you should not have very high expectations - trying to sort out a real-time performance and produce readable notation is something that really requires human expertise' computers tend to not be very good at it. You'll get something, for sure, and it should be "accurate", but probably all but unreadable. Better to stick to entering notes yourself so you have control over the spelling of the notes and rhythms.

MuseScore 3 will be able to basically do exactly what you described, though.

You can play the music into a DAW and then quantize it, but, I have never achieved satisfactory results by attempting to capture an actual human performance into a score, using any software at all.

An actual human performer is guided by what is written in the score, but what you hear never exactly matches it.   (If it does, it sounds “mechanical.”)

I found myself spending more time trying to make the score look right, that way, than by simply typing the darned thing in.   (It is somewhat handy to use a keyboard to enter individual notes.   But, “over time?   Fuhgeddaboudit.”)   Maybe 3.0 will be wonderful and will change my point-of-view completely.