the skyscraper might make quite a cool 3 point perspective, 1 point even, if you do it right.
otherwise theres some pretty difficult for measurments for perspectives.
I would go learn how to do a proper constructed 1 or 2 point befor freehanding it.
the vanishing points youre using are pretty severe, would need a pretty nifty camera to get the effect IRL
None of your windows reflect the vanishing points, nor do any of the roofs.
anyway, perspectives are pretty difficult to freehand even if you have learnt them.
nice attempt, i guess.