Rotate screen on iph 11

Not all screens will rotate. What are you viewing that you are trying to rotate? You can check to make sure the Orientation Lock is not turned on by going to Control Center and checking on the icon that looks like a small padlock with a circular arrow around it. If it is white and red, it is on. Tap on it again to turn it off. See this page from the iPhone User Guide, Change or lock the screen orientation on iPhone - Apple Support

The icon should be in Control Center. Swipe downward from the top right corner of the iPhone to bring down Control Center. You should see it there. See if this page from the iPhone User Guide helps, Use and customize Control Center on iPhone - Apple Support