Hi,
It seems as though the camera’s LCD display either has a loose cable connection or it is faulty.
Here’s the ifixit [guide|78743] guide.
This shows how to open the camera and check that the LCD flex cable connection to the motherboard is securely connected, (see image at Step.10). If it secure then as a DIY repair all you can do is to replace the LCD display and check if it now works OK, because if it is faulty it cannot be repaired, it has to be replaced.
Search online for ''Canon PowerShot SX530 HS Camera LCD Display Screen'' to find suppliers that suit you.