Are you not allowed to switch the position of 저는 and 여기에서? There's another question in this unit that allows you to put 여기 at the beginning of the sentence, so I'm confused why you can't do that here.
Yes, you can. I presume your switched answer wasn't accepted when you were writing that, but it is currently accepted.
you can, but 저는 coming before 여기에서/여기서 is more 'standard'
Does this mean : I leave this place?
(1) exit a mode of transport (train, plane, bus, car...) = ~에서 내리다
(2) exit at this point/place = ~에 내리다