Hi,
The screen most probably has been damaged internally by the fall and will have to be replaced. It cannot be repaired.
Here’s a [https://www.youtube.com/watch?v=xRtTlIFXjQk|video] that shows how to replace the screen in the phone.
Replacement screens are available online. Just search for ''Galaxy J5 SMJ530F LCD screen'' to get results for suppliers of the part.
If you find replacing the screen yourself is too daunting, contact a reputable, professional mobile phone repair service and ask for a quote.