Hi Elizabeth!
Have you tried turning it off and back on? This is not the same as putting your iPhone to sleep. Here's how to do it:
Press and quickly release the volume up button, press and quickly release the volume down button, then hold down the side button until the power off / medical id / emergency call screen comes up. Drag the power off slider. I'd recommend that, once your phone is turned off, you wait between 30 and 60 seconds, then hold down the side button until the Apple logo appears. The phone will boot up and you can continue using it as normal.