issued in deleting photos and videos and system updates issues

I'm trying to delete some photos and videos in my photo album here in my iphone 7plus. But the problem is when im trying to delete it, it cannot deleted. How can i fix it? And some of my videos is error and cannot viewed. Also im trying to check for an update there is an error occurred when Checking for an update. And im deleting also some application in my iphone and its not deleting also.. I think the issue in my problem is the new system update which is 13.5.1.