What is the lock symbol with the circle around it in the upper right hand side of screen and what does it mean?

That means that the orientation is locked. This is useful when reading in bed on your side, etc so that the content faces you. To shut that off, just open Control Center by swiping up from the bottom edge of the screen. Then tap the identical icon in the popup.

That would be rotation lock. See below.

If the screen doesn't rotate on your iPhone, iPad, or iPod touch - Apple Support

Yes, the two would be completely unrelated... Go ahead and do another separate Forum post!