My screen does not rotate when I turn my phone

Try first power cycling your phone. Turn it off, wait a moment, then turn it back on again. After it finishes rebooting, check. Did you try pressing the button to turn it on, and then press to turn it back off again?

Don't worry about it. I understand completely. Sometimes even for those of us that spend a great deal of time answering questions here, we tend to assume sometimes that users have tried some of the simple things and don't even recommend them. Either way, glad you got it working. Come back if you experienced any more problems.

Exactly which screen are you attempting to turn? Not all screens can rotate from portrait to landscape orientation.

So what troubleshooting have you tried? What things have you done to try to get it to work, besides checking to see that the orientation lock is not on in Control Center?